The interest started last season. Discussions began in the days after the World Series and carried into the Major League Baseball general managers meetings in November and winter meetings in December.

With two weeks until the opening of spring training, the Mariners are in the final stages of completing a trade to acquire St. Louis Cardinals infielder/outfielder Brendan Donovan in a three-team deal involving the Tampa Bay Rays, sources with knowledge of the deal have told The Seattle Times.

Per sources, the Mariners are sending a pair of former first-round picks to the Cardinals — switch-pitcher Jurrangelo Cijntje and outfielder Tai Peete. Seattle is sending young third baseman Ben Williamson to the Rays. Tampa is giving up a draft pick and another prospect in the deal.

While the framework of the deal has been finalized, the teams were still in the process of reviewing medical information and notifying players, which is why it hasn’t been announced yet.

Donovan, entering his age-29 season in 2026, was a first-time All-Star in 2025, and he won a utility player Gold Glove as a rookie in 2022.

In four seasons in St. Louis, Donovan has had a career slash line of .282/.361/.411 (. 772 OPS) with a 117 OPS+ (17% better than league average), 40 homers, 97 doubles and a 11.1 bWAR.

Donovan, who is in his second year of arbitration eligibility, agreed to a $5.8 million contract for 2026 with the Cardinals. The Mariners will have two total seasons of club control with Donovan becoming a free agent after the 2027 season.

He has a career on-base percentage of .361, making him a leading candidate to bat at the top of the Mariners lineup.

The top five hitters in the Mariners lineup — Donovan, Julio Rodríguez, Cal Raleigh, Josh Naylor and Randy Arozarena — have been All-Star selections in the past two seasons.

Donovan’s 13% strikeout rate in 2025 was among the lowest in MLB, and his 119 wRC+ ranked fifth among regular MLB second basemen.

Per FanGraphs’ metrics, Donovan had a higher fWAR (2.9) in 2025 than Jorge Polanco (2.6), the middle-of-the-order slugger the Mariners just lost to the New York Mets in free agency.

Cijntje, who was taken with the 15th overal pick in the 2024 draft, was just in Seattle to participate in FanFest. The Mariners announced that the plan was for him to focus on throwing right-handed exclusively in games, while still working on throwing from the left side in bullpens.

Peete, 20, was part of a trio of high school players selected in the first round of the 2023 draft along with shortstop Colt Emerson and outfielder Jonny Farmelo.

This story will be updated.