Brendan Donovan Headlines Cardinals–Mariners–Rays Trade | Fantasy Baseball Impact

The MLB transactions keep coming, so we'll continue breaking things down here. Let's discuss the three-team trade between the Cardinals, Mariners and Rays from Monday.

Brendan Donovan was the key piece in the deal, moving from St. Louis to Tampa Bay. St. Louis received Jurrangelo Cijntje, Tai Peete, Colton Ledbetter and two Round B draft picks in the deal. Tampa Bay got Ben Williamson from the Mariners. 

Let's discuss the real world and fantasy baseball implications of the deal.

For the latest player updates, be sure to head to FantasySP to utilize the real-time player news engine for all sports. The player news engine is the most robust and fastest player news system in fantasy sports. Signing up for a FantasySP membership can help you track all your fantasy players.

Player Stats

Donovan has been in the big leagues for four years, all with St. Louis. He has a career .282 average and .361 on-base percentage.

He played in 118 games last season, sporting a .287 average and .353 OBP. In his 132 hits, Donovan had 32 doubles and 10 home runs. Donovan also had 50 RBIs, 64 runs scored, three stolen bases, 42 walks and 67 strikeouts.

Donovan mostly played second base last season. He also has appeared at first and third base, plus shortstop, in his career. Donovan also has played left and right field, so he's a versatile defender if Seattle needs him to be.

Williamson made his big league debut in 2025, playing in 85 games for the Mariners. He had a .253 average and .294 OBP. Williamson had 70 hits, including 13 doubles and a home run, plus 21 RBIs, 36 runs scored, five stolen bases, 15 walks and 64 strikeouts.

Williamson played third base exclusively. He played second base and shortstop in the minor leagues, so he too could move around a bit.

Cijntje is notable because he's a switch-pitcher. It was just revealed that he's going to focus on right-handed pitching only this season.

He's the No. 91 prospect in all of baseball and is 22 years old. Cijntje has a 2026 ETA after being the 15th overall pick in 2024. He pitched at High-A and Double-A last year, posting a 3.99 earned run average over 108 1/3 innings.

Peete is the Cardinals' No. 15 prospect and plays the outfield. He's 20 years old and has a 2027 ETA after being the 30th overall pick in 2023.

In three years and 264 minor league games, Peete has a .247 average and .318 OBP. His best tools are his power and running, while also being a plus-defender.

Ledbetter was the Rays' No. 24 prospect before the trade. The 24-year-old outfielder has made it up to Double-A, so he'll be a call up option in 2026 or 2027.

Ledbetter has played in 253 minor league games over three years. He has a .269 average and .341 OBP. He has a bit of pop, and some speed to burn.

Mariners' Outlook

Donovan is expected to play third base for Seattle, so it made sense to part ways with Williamson. Donovan is projected to hit leadoff.

That would put him in front of the likes of Cal Raleigh, Julio Rodriguez, Josh Naylor and Randy Arozarena, which means Donovan is set up for a good fantasy season.

The trade is definitely a positive for Donovan after the Cardinals sold a bunch of their best players away this offseason. In Seattle, he's backed by a number of good hitters, and there's enough talent at the bottom of the order to also add some stats for Donovan.

Donovan's fantasy stock is definitely up after the trade, and his presence is a plus for the rest of the Mariners' lineup.

Raleigh, Rodriguez and Naylor are already very good fantasy options, and the addition of Donovan only helps their causes. Those three and Donovan probably all saw their average draft positions rise a bit from this trade.

Arozarena could see a slight increase in fantasy value from the deal, but he's a step below the top four in the Seattle order.

Guys at the bottom of the order (J.P. Crawford, Victor Robles) could also see a slight uptick with Donovan hitting at the top of the order now. Dominic Canzone and Cole Young are in projected platoons with Leo Rivas and Rob Refsnyder. Luke Raley and Andrew Knizner are the other projected bench players for Seattle.

Crawford and Robles could become standard league fantasy assets with some strong hitting, but all those bottom-of-the-order guys are more deep-league assets to kick off the season. Having Donovan behind them is definitely a plus for whoever can get on base consistently though.

I really like the addition of Donovan in Seattle. It's a plus for the team and fantasy outlooks, and puts the Mariners in a spot to contend in the American League.

Cardinals' Outlook

St. Louis' lineup is absolutely decimated after several offseason moves, and there's not many good fantasy options left.

Lars Nootbaar is in a projected platoon atop the order with Jose Fermin. Ivan Herrera, Alec Burleson, Nolan Gorman, Masyn Winn, J.J. Wetherholt, Jordan Walker, Pedro Pages and Victor Scott II are the projected starters otherwise.

Along with whoever is sitting in the projected platoon, Yohel Pozo, Thomas Saggese and Nathan Church are the projected bench guys.

St. Louis is definitely looking to the future, but it's opened opportunities for several players. Wetherholt is a highly-touted prospect that has a much easier path to a starting role with the MLB team right away this season. He's a name to track as the season nears.

Anyone starting consistently in St. Louis has the chance to be a good fantasy asset. Burleson, Herrera, Nootbaar and Winn are the top returning fantasy players (in points leagues) from last season. I'll be interested to see who the best draft options are, and there's a chance for anyone to become a fantasy asset, so the Cardinals are a team to watch, despite what might be a not-so-great season.

Adding Cijntje, Peete and Ledbetter adds more fuel for the years to come in St. Louis. None of those guys are projected to make the big league roster right away, but any of them could be called up in 2026.

Cijntje is a pitcher I've been intrigued by, since he is a switch-pitcher. Focusing on just being a righty (although that could change with him now in St. Louis) could allow him to take a step forward and eventually earn a call up. He's a name to keep tabs on this coming season, but is a better dynasty asset for now.

Peete and Ledbetter are just dynasty assets for now. Good numbers in the minor leagues could allow them to reach the big leagues eventually, and then we'll see if either can step up and lock down daily starting roles. The massive overhaul of the St. Louis roster definitely works in the favor of younger players and prospects though, so don't rule out anyone making an impact this coming season.

Rays' Outlook

Tampa Bay is kind of an afterthought in this deal, but Williamson should be a part of the big league team to open the 2026 season.

He's projected to be in a platoon. Junior Caminero is the everyday third baseman, but he could split time with Gavin Lux at second base, or maybe even Taylor Walls at shortstop.

Williamson is just a deep-league fantasy asset if he's indeed in a platoon to open the season. He's on the short side of the platoon as well, so Williamson is not that big of a fantasy asset.

We'll see if the change of scenery unlocks Williamson in any way and he takes off with his new team. Right now though, he's just not a very big fantasy asset.