Three-time All-Star right fielder Carlos Gonzalez has offers from the Astros, Giants, and Padres, according to an ESPN report.
Gonzalez, 32, struggled for most of the 2017 season, finishing with a .762 OPS and 14 home runs over 136 games for the Rockies.
Over the final month of the season, he slashed .377/.484/.766 with six homers as Colorado reached the postseason for the first time in eight years via a National League Wild Card spot.
The Giants, in particular, have been in the market for outfielders, with veteran Denard Span being traded to the Rays as part of the deal that sent Evan Longoria to San Francisco, and 34-year-old Hunter Pencecoming off a season in which he posted the lowest OPS (.701) of his career.
San Francisco has also been most recently linked to free-agent right fielder Jay Bruce, and the Pirates' Andrew McCutchen.
The Astros could be looking to add another left-handed power threat in the lineup now that Carlos Beltran has retired.
The Padres have been linked to free-agent first baseman Eric Hosmer, though they have also been active on the trade market, acquiring right-hander Bryan Mitchell and third baseman Chase Headley from the Yankees, as well as shortstop Freddy Galvis from the Phillies earlier this offseason.