The San Francisco Giants and Seattle Mariners have become the leading candidates to acquire St. Louis Cardinals infielder Brendan Donovan, according to reports. The Cardinals are seeking multiple top prospects in return for the 28-year-old All-Star, who has two years of team control remaining. Discussions have intensified, though St. Louis will only proceed if the offer is substantial.
The St. Louis Cardinals continue their offseason rebuild under president of baseball operations Chaim Bloom, with All-Star infielder Brendan Donovan emerging as a prime trade candidate. Reports from The Athletic indicate that the San Francisco Giants and Seattle Mariners are frontrunners in negotiations for the versatile left-handed hitter, who earned his first National League All-Star nod in 2025.
Donovan, 28, posted a .287/.353/.422 slash line with 32 doubles, 10 home runs, and 50 RBI over 118 games last season. Primarily playing second base in 2025, he has experience across six positions, including left field in 2024 when he set career highs with 34 doubles, 14 homers, and 73 RBI. Across four MLB seasons, Donovan maintains a .282/.361/.411 line with 40 home runs and 202 RBI. He won a Gold Glove in 2022 and finished third in NL Rookie of the Year voting that year. Projected to earn $5.4 million in arbitration for 2026, Donovan remains under team control through 2027.
The Cardinals are holding out for a significant return, specifically multiple well-regarded prospects, and will not trade Donovan unless "blown away" by the package. Talks with the Giants have included mentions of left-handed pitcher Carson Whisenhunt, San Francisco's No. 7 prospect, who debuted in 2025 with a 2-1 record, 5.01 ERA, 16 strikeouts, and six walks in 23 1/3 innings over five starts. Also discussed is middle infielder Gavin Kilen, the Giants' No. 3 prospect and a 2025 first-round pick (No. 13 overall), who hit .205 in 10 games at Low-A San Jose.
For the Giants, acquiring Donovan could bolster their infield, especially with second baseman Casey Schmitt recovering from offseason left wrist surgery. Schmitt is expected to be ready for spring training but may share time with Donovan's versatility under new manager Tony Vitello. The Mariners, fresh off losing Jorge Polanco to the Mets in free agency, also seek infield depth. While no deal is imminent, the Giants and Mariners' strong farm systems position them well to meet St. Louis' demands.