Chris Cotillo of MassLive.com added that the move was "not a huge surprise" and noted Bradley is still a "prime trade candidate."
According to The Athletic's Ken Rosenthal, the Arizona Diamondbacks "would have interest" in Bradley if he was non-tendered and are "exploring every center field option."
Bradley is expected to command around $11 million in arbitration, per Rosenthal. The Red Sox will want to clear that off their books as they attempt to get below the $208 million luxury-tax threshold.
Even if Bradley departs, Rosenthal noted it "would not necessarily affect the Sox thinking on trading right fielder Mookie Betts; for the right offer, the Sox still might make such a move. But it remains questionable they will get that offer, with Betts projected to get $27.7 million in arbitration in his final season before free agency."
The 29-year-old Bradley hit just .225 in 2019, though he had 21 homers, 62 RBI and 69 runs with a .738 OPS and 2.0 WAR. He hasn't been able to replicate his breakout 2016 season, when he hit .267 with 26 dingers, 87 RBI, 94 runs, an .835 OPS and 5.3 WAR, all career highs.
His defensive WAR of 0.4 in center field this past season was also his lowest since his rookie season in 2013.
Nonetheless, he'd be an upgrade for several teams, so a trade market should materialize.