Royals Address A Couple of Important Needs in Trade With Brewers

On Saturday, the Royals and Brewers made a headlines-grabbing swap in an effort to boost both of their clubs. Kansas City acquired outfielder Isaac Collins and reliever Nick Mears in exchange for reliever Angel Zerpa. 

After acquiring free-agent outfielder Lane Thomas earlier this week, the Royals have now improved their outfield depth with this latest addition from Milwaukee. That said, it doesn't seem like Royals GM JJ Picollo is done just yet. Rogers wrote that the Royals front office is still looking to add to their lineup this offseason to improve an offense that ranked 26th in OPS and runs scored a season ago.

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The Royals were after offense in this trade, acquiring Collins for his contact and on-base ability. On Thursday, Kansas City came to an agreement with free-agent outfielder Lane Thomas on a one-year deal, which still hinges on a physical. That’s two new outfielders who the Royals believe lengthen their lineup and better support the core of the position player group. But sources indicated that those two acquisitions don’t necessarily mean the Royals are done looking for bats this winter.

Royals fans have been expecting a significant outfield upgrade this offseason, especially with rumors connecting Kansas City to big-name outfielders like Teoscar Hernandez, Jarren Duran, and Luis Robert Jr. That said, they shouldn't overlook this vital deal with the Brewers. This move checked a lot of boxes for Kansas City, and it still gives them the roster and financial flexibility they need for a deal later this offseason.  

Let's look at who the Royals acquired in Collins and Mears and what they gave up in Zerpa, who has been a key part of the Royals' bullpen the past couple of seasons.

Royals Get Polished, Controllable Outfielder in Isaac Collins

The main prize in the deal for the Royals is Collins, a 28-year-old outfielder who finished fourth in the NL Rookie of the Year race last season. A ninth-round pick out of Creighton, Collins isn't precisely a high-ceiling kind of player, but he provides the type of profile that the Royals were missing in the outfield last season until Mike Yastrzemski came over at the Trade Deadline. 

In 441 plate appearances, Collins slashed .263/.368/.411 with a .779 OPS and 122 wRC+. He also hit nine home runs, scored 56 runs, collected 54 RBI, stole 16 bases, and posted a 0.61 BB/K ratio. For context, Collins' BB/K ratio would've been the fourth-best mark of Royals hitters with 10 or more plate appearances last season, according to Fangraphs. 

Furthermore, Collins' strong plate discipline wasn't just evident in his BB/K ratio, but also in his strong O-Swing%, Whiff%, and BB%.

The exit velocity and batted-ball metrics were a bit of a concern for Collins last season. He ranked in the 25th percentile in average EV, 16th percentile in barrel rate, and 33rd percentile in hard-hit rate.  His 87.8 MPH average exit velocity would have ranked 10th last year among Royals outfielders, tying him with Kyle Isbel, who had a similar average EV. Thus, some feel that Collins may be a regression candidate in 2025, which Jack Stern of Brewer Fanatic wrote about in December. 

There certainly are some concerns with Collins when looking at his Statcast profile. That said, there are a few positives about his outlook in Kansas City for 2026 and beyond.

First, he did a good job of pulling the ball well to both fields (he's a switch-hitter). When applying his 2025 spray chart to Kauffman Stadium, it seems like Collins wouldn't have missed a beat, though a few of the home runs to right field may have been short. Other than the home runs, his spray profile should transition seamlessly to Kansas City's home confines. 

Another positive about Collins is that his "struggles" seemed to stem from a September slump, which colored Brewers fans' outlook for him next season.

When looking at his splits via Savant, he posted a .664 OPS in the last month of the year after three-straight months of an OPS over .845. While it makes sense that the Brewers may have used him more sparingly going into the postseason due to his end-of-the-season issues, his overall performance from 2025 was still strong and worthy of regular playing time.

He also still showcased substantial OBP numbers throughout 2025, even in months that weren't great batting-average-wise. In September, his OBP was .345 despite a .191 average. In April and May, his OBP marks were .306 and .319, respectively. To compare, Royals outfielders ranked last in OBP with a .283 mark, according to Fangraphs. Thus, even when Collins was at his worst last year, his profile is still a significant upgrade over what they trotted out last year in the outfield.

Collins' rolling xwOBA chart also showed some positive trends at the end of the season after an initial dip in September. That indicates that Collins may have also been a victim of some rough batted-ball luck, which should correct itself in 2026.

Finally, the projections seem to paint Collins in a positive light for 2026.

Steamer projects Collins to post a .232/.335/.370 slash with a .704 OPS and 101 wRC+. He is also projected to have a 0.52 BB/K ratio, .137 ISO, and .314 wOBA. Obviously, many of those projections are a regression from his 2025 numbers. However, the BB/K ratio is pretty stable, and the wOBA matches the second-best mark for Royals outfielders a season ago (which belonged to Adam Frazier). 

Collins may not be THE answer in the Royals outfield next year and long-term (though he doesn't become a free agent until 2031). But he is AN answer in the sense that he gives Kansas City the kind of plate discipline and overall skills (he had a +4 OAA defensively last year) that the Royals desperately need. 

Nick Mears Boosts the Royals Bullpen in Chase and Whiffs

The Royals' bullpen showed significant improvement in 2025 thanks to Carlos Estevez, who brought stability to the closer's role, and to better overall depth in the middle innings. Kansas City's bullpen ranked 7th in reliever ERA, 12th in WHIP, and fourth in BB/9. 

However, Royals relievers struggled in one particular category: strikeouts. The group ranked 29th in K/9, and while it worked out for them in 2025, it's unlikely that the bullpen would be as fortunate in 2026 without some upgrades and significant improvement in some critical areas.

When it came to why the bullpen struggled, Royals relievers had trouble generating chase and whiffs, which coincided with their strikeout struggles last year. According to Fangraphs, the Kansas City bullpen ranked 28th in O-Swing% (29.7%) and 30th in SwStr% (9.8%). 

Mears helps the Royals' bullpen in both of those categories. He posted a 37.3% O-Swing% and generated a 13% SwStr%. His 28% CSW (called-strike plus whiff) rate was also much better than the Royals bullpen's 26.9% CSW rate as a group, which ranked 27th last season. 

When it comes to his profile, Mears offers a three-pitch mix with substantial TJ Stuff+ numbers, which has helped him perform well in the chase and whiff categories.

Mears' overall TJ Stuff+ was 107 last year, with his four-seamer, slider, and curveball posting grades of 63, 59, and 54, respectively. Those are all above-average marks, and he also posted above-average results in Zone% (55.7%) and chase rate (33.2%). 

An undrafted pitcher out of Sacramento (he went to Rocklin High School and then Sacramento City College), his best offering is his slider, which not only sported a 108 TJ Stuff+ but also a 46% chase and 38.4% whiff rate. Mears was effective against lefties and righties with the pitch, as he sported a .193 wOBA and 27.4% whiff rate with the slider against lefties and a .204 wOBA and 44.6% whiff rate against righties.

A further breakdown of his slider's performance against lefties and righties can be seen in the data and heatmap below (courtesy of TJ Stats).

Against lefties, he tended to attack hitters with the slider more middle and down. Against righties, he attacked more low and away. Both approaches produced results, as illustrated by his CSW marks of 35% and 40.2% against lefties and righties, respectively. 

The clip compilation below, showing strikeouts of Jurickson Profar and Julio Rodriguez, also demonstrates how productive Mears could be when he commanded the slider effectively.

The primary concern with Mears is his fastball, which had good TJ Stuff+ numbers, but didn't generate much chase (22.7%) or whiff (14.6%). When looking at his four-seamer heatmap and data via TJ Stats, he did a good job of locating the ball up, but he seemed to struggle to get CSW and to give up productive contact (as illustrated by the mediocre xwOBACON marks).

Allowing productive contact seemed to be an issue overall, as demonstrated by his .405 xwOBACON allowed last year. That said, if he can improve his xwOBACON on the four-seamer, it could go a long way toward better overall results in 2026.

He certainly will be an interesting project for pitching coach Brian Sweeney and new assistant pitching coach Mike McFerran this spring in Surprise. If they can help with his four-seamer shape and command, he could end up being a solid setup man for the Royals in 2026 and beyond. 

Royals Willing to Part With Angel Zerpa

This offseason, Rogers reported that the Royals were interested in acquiring a left-handed reliever who could be effective primarily against left-handed pitchers. That made me wonder if the Royals were planning on trading one of their lefties on the 40-man roster: Zerpa, Daniel Lynch IV, or Bailey Falter.

Yesterday, Picollo showed they were willing to trade away Zerpa, even though he was one of the lefty relievers Matt Quatraro heavily utilized in medium-to-high-leverage situations.

The Venezuelan lefty has always been a bit of a dilemma for the Royals the past couple of seasons. On one hand, he didn't walk batters (2.64 K/BB ratio), and he demonstrated durability, pitching 64.2 innings for the Royals last year. His ERA was a bit high for a setup man at 4.18, but his FIP was much better at 3.86, which was a career-high. 

And yet, it felt like the Royals had maxed out their hand with Zerpa and his outlook. He was a fine middle-innings reliever, but he didn't have the TJ Stuff+ profile to be anything more than that, as illustrated below.

Zerpa sported a 97 overall TJ Stuff+ last year, with his sinker and slider the only pitches with grades over 50. He did flood the strike zone with a 54.7% zone rate. However, he sported mediocre chase (26.7%) and whiff (16.4%) rates. Considering the Royals' problems in those two areas last year, it made sense that the Royals were willing to part with Zerpa in a trade, especially if it meant getting a pitcher who could be better than Zerpa in whiff and chase. 

Now, the Brewers are an excellent organization, known for developing pitchers on a budget. Zerpa could be a success story for Milwaukee, and if so, kudos to them for another positive development. To be fair to Zerpa, his Steamer projections paint a rosy picture for 2026: 3.44 ERA, 3.62 FIP, 2.83 K/BB ratio, and 1.27 WHIP in 60 IP. 

That said, the Royals needed to give up something to get something needed in return this offseason. Zerpa was the odd man out in this case, and based on his metrics and outlook, I think trading the lefty was well worth the return they received in Collins and Mears. 

(Plus, Baseball Trade Values felt the same way, too.) 

Let's hope Picollo has more stellar moves like this one up his sleeve this winter, especially with their goal of returning to the postseason after missing out in 2025.