Giants and Mariners Locked in Secret Duel for All-Star Brendan Donovan—Who Will Win the Blockbuster Trade?

Amidst an offseason marked by quiet free-agent activity, the San Francisco Giants are reportedly eyeing a significant roster upgrade through the trade route—targeting none other than All-Star second baseman Brendan Donovan. According to sources cited by The Athletic’s Katie Woo, both the Giants and Seattle Mariners have positioned themselves as leading contenders to acquire Donovan from the St. Louis Cardinals. At 28, Donovan brings a versatile skill set to the table, having not only honed his craft at second base but also demonstrated flexibility by patrolling left field extensively last season. His steady offensive production and defensive adaptability could provide a much-needed boost to first-year Giants manager Tony Vitello’s squad. Meanwhile, discussions are ongoing involving San Francisco’s top prospects, such as pitcher Carson Whisenhunt and middle infielder Gavin Kilen, as the teams negotiate for a deal that could reshape the Giants’ future. Yet, with the Cardinals demanding a standout return, the Giants face stiff competition from the Mariners, known for their deep farm system and resources. As the trade whispers gain momentum, this potential move might reshape the Giants’ infield dynamic and offer exciting possibilities for their 2026 roster construction. LEARN MORE

Giants, Mariners front-runners to trade for All-Star Brendan Donovan, per report originally appeared on NBC Sports Bay Area

While the Giants have been quiet on the free-agent market, they could look to upgrade their roster via trades, and they have their eyes on an All-Star National League second baseman.

The Giants and Seattle Mariners have emerged as the front-runners to acquire Brendan Donovan from the St. Louis Cardinals, The Athletic’s Katie Woo reported Saturday, citing sources familiar with negotiations.

The 28-year-old Donovan has been a solid contributor for the Cardinals during his four-year MLB career, and he earned his first All-Star nod last season.

In 118 games last season, Donovan slashed .287/.353/.422 with 32 doubles, 10 homers and 50 RBI. In 2024, he recorded career highs in doubles (34), home runs (14) and RBI (73).

While Donovan primarily played second base in 2025, he predominantly played left field in 2024, so he would provide first-year Giants manager Tony Vitello with a versatile option.

Per Woo, the Giants and Cardinals have discussed several top prospects who could be part of a potential Donovan deal, including left-handed pitcher Carson Whisenhunt and first-round 2025 MLB Draft pick Gavin Kilen, who played for Vitello at Tennessee.

Whisenhunt, 25, made his long-anticipated MLB debut last season and struggled over 23 1/3 innings with the Giants. He posted a 5.01 ERA and just 16 strikeouts in five starts. But MLB Pipeline still had him ranked as San Francisco’s No. 7 prospect to end the season.

Kilen, a middle infielder who ranks as the Giants’ No. 3 prospect, hit .205 in 10 games with Low-A San Jose after being drafted No. 13 overall.

But Woo also reports, citing multiple team sources, that the Cardinals won’t trade Donovan unless they are “blown away by the return.”

So the Giants will have to come to the table with a strong offer and beat out the Mariners, who have one of baseball’s best minor league farm systems.

Donovan wouldn’t be a one-year rental, as he is arbitration-eligible in 2026 and 2027. MLB Trade Rumors projects that Donovan will earn $5.4 million in arbitration next season.

At the moment, Casey Schmitt is slated to get most of the reps at second base in 2026, but he underwent left wrist surgery this offseason and won’t start camp on time in February. He should be ready for spring training, though.

“We don’t think he’ll be slowed during spring training at all. He should be fine,” general manager Zack Minasian said on the “Giants Talk” podcast earlier in December. “I thought Casey made a lot of positive strides last year: At-bat quality, learning a new position, there’s still some upside there, and I’m excited to see what he can do going forward.”

If the Giants acquire Donovan, he could split time at second base with Schmitt while both players move around the field, making use of their versatility.

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