Mariners add established bat to infield mix
Seattle finally gets Brendan Donovan. A seemingly ideal addition for a club intent on reaching the World Series and promoting prospects from within in 2026.
Today, the Mariners added a much-needed established bat to bolster their current lineup, who can also serve as a bridge to the organization’s deep stable of infield prospects. That player is infielder Brendan Donovan, acquired from the Cardinals in a three-way deal involving the Rays.
The Cost
To land Donovan, Seattle sent third baseman Ben Williamson to Tampa Bay and starter Jurrangelo Cijntje and outfielder Tai Peete to St. Louis.
Williamson debuted with the Mariners last year, producing a suboptimal .310 SLG and 76 wRC+. Even less appealing, a 3.3-percent barrel rate that was 26th lowest among 274 hitters with 200 batted ball events. Defensively, the second round pick demonstrated promise with a middle of the pack zero FRV.
Fielding Run Value (FRV) is Statcast's metric for capturing a player’s overall measurable defensive performance. ZERO is always average.
As for Cijntje and Peete, both are former first round picks. MLB prospect pipeline ranked Cijntje as its 91st best, while Keith Law of The Athletic didn’t include Cijntje or Peete in his annual top-100 prospect list.
The ambidextrous Cijntje is a fascinating prospect. It’s worth noting Seattle announced over the weekend that he’d be pitching as a right-hander in 2025, although the door was left open for a return to being a dual-armed hurler again in the future. That decision now rests with Cardinals management.
Peete primarily played center field in 2025 and reportedly performed well with his glove. That said, it’s tough for this nerd to ignore a 30.6-percent strikeout rate in each of the last two seasons at Class-A Modesto and High-A Everett. Then again, Peete is entering his age-20 season. The pathway to growth and development remains wide open.
The Get
Conversely, Donovan is exceptional at making contact. In 2025, his 13-percent strikeout rate was 13th lowest among 145 qualified hitters. Mariners with similar success included Josh Naylor (13.7%) and Jorge Polanco (15.6%).
Last year, Donovan’s .353 OBP tied for 30th best among qualified hitters. Adding his superb on-base ability to a batting order that already includes Cal Raleigh (.359 OBP), Josh Naylor (.353), J.P. Crawford (.352), Randy Arozarena (.334), and Julio Rodríguez (.324) should enhance Seattle’s ability to generate RBI opportunities in 2026.
Another lens to view Donovan through is offensive value. His 119 wRC+ signals he was nearly 20-percent more productive than the average hitter in MLB last year.
Weighted Runs Created Plus (wRC+) quantifies how a hitter’s total offensive value compares with the league average after adjusting for park effects. League-average is always 100. Therefore, a wRC+ of 150 means a hitter was 50-percent more productive than the average player. An 80 wRC+ would be 20-percent below average.
Something else to consider - Donovan’s uncanny consistency. Last year, the German-born All-Star’s production numbers were very similar to what he delivered to St. Louis since debuting in 2022.
Donovan’s Unwavering Production
2025: .287 AVG, .353 OBP, .422 SLG, 119 wRC+
Career: .282 AVG, .361 OBP, .411 SLG, 119 wRC+
It’s worth noting Donovan’s 119 wRC+ over the last four seasons ranks 56th among 306 hitters with at least 1,000 plate appearances. A review of this list reveals he’s surrounded by many notable names, including several current and former Mariners.
Players with a Similar wRC+ to Brendan Donovan Since 2022*
Christian Yelich (123)
George Springer (123)
Josh Naylor (123)
Brandon Nimmo (121)
Randy Arozarena (121)
Trea Turner (120)
Max Muncy (120)
Carlos Correa (120)
Bo Bichette (120)
Riley Greene (119)
Brendan Donovan (119)
Ian Happ (119)
Eugenio Suárez (119)
Luke Raley (119)
Taylor Ward (119)
Luis Arraez (118)
Teoscar Hernández (118)
Jazz Chisholm Jr. (117)
Ryan O’Hearn (117)
Matt Chapman (117)
Jarren Duran (116)
Anthony Santander (116)
Giancarlo Stanton (116)
Vinnie Pasquantino (115)
Jorge Polanco (115)
Adley Rutschman (115)
Jordan Westburg (115)
* 1,000 PA minimum
Where Donovan plays in the field for the Mariners will be determined in Spring Training and likely evolves as the season progresses. But based on his history, the 29-year-old will see time at multiple positions.
Brendan Donovan’s MLB Innings by Position
1B (151)
2B (1,757)
SS (106)
3B (270)
LF (1,246)
RF (205)
To this blogger, Donovan playing second base and third base makes the most sense. This opinion is based on the team’s current situation at those two positions.
Rookie Cole Young led Seattle with 68 second base starts last year followed by Polanco (34). Polanco is now a Met, while Young struggled at the plate late last season. Moreover, his minus-seven FRV was second worst among second basemen with only Brandon Lowe behind him.
The departures of Eugenio Suárez and Williamson leaves Miles Mastrobuoni as the only player on the 40-man roster who started MLB games at third base in 2025. That said, the Mariners likely give top prospect Colt Emerson a real opportunity to start the season at the hot corner. A word of caution: Emerson doesn’t turn 21 until July. Therefore, managing expectations is advisable.
And that’s where Donovan comes in.
Donovan can play anywhere in the infield with second base being his primary spot in 2025. He made 91 starts at the keystone and also started five contests at shortstop and another 18 in left field. I suspect the position the veteran plays most often will hinge on the performance of the inexperienced cadre of Young, Emerson, Ryan Bliss, and Leo Rivas.
There’s a lot to like about Donovan. But we should acknowledge areas that could potentially dampen the very high expectations Mariners fans have for the University of South Alabama product.
The left-handed hitting Donovan was extremely productive against right-handed pitching last season. However, there was a significant gap in his platoon splits.
Donovan’s Platoon Splits (2025)
vs RHP: .315 AVG, .383 OBP, .471 SLG
vs LHP: .230 AVG, .292 OBP, .322 SLG
To be clear, I’m not suggesting Donovan is a platoon candidate - he’s not. But it’s worth noting that southpaws enjoyed much more success against the seventh round pick than their right-handed counterparts in 2025.
Another factor to mull over. Injuries have negatively impacted Donovan’s availability in two of his four big-league campaigns. In 2023, he missed the final two months of the season with an elbow issue. Last year, the one-time Gold Glove winner underwent sports hernia surgery in October after being sidelined with a groin strain in August and September.
Again, no alarm is being sounded. But it’s important to recognize Donovan missed 25-percent of Cardinal games over the past three years.
Finally
In two ways, Donovan is an ideal pickup for the Mariners. His presence solidifies and elevates the lineup of a team with World Series aspirations. Moreover, his positional versatility will provide opportunities for the organization’s stable of prized infield prospects to potentially contribute in 2026 and beyond.
That’s a win-win scenario for the team and its fan base.
My Oh My…