The Phillies were one of the most active teams this offseason, and don’t be surprised if they try to make some major in-season upgrades.

According to MLB.com’s Jon Paul Morosi, Philadelphia has been doing due diligence on Giants left-hander Madison Bumgarner since Spring Training. The 29-year-old is an impending free agent who could become available this summer if San Francisco falls out of the race.

“The Phillies, of course, they were able to make some aggressive moves in the winter time, as we all know, to bring in three All-Star position players, but they’ve got that one need for that lefty starter,” Morosi said Thursday night in an appearance on FS1. “And if you’re going to go all in on one year to make a World Series run, who better to get than Madison Bumgarner?”

While Philadelphia has Aaron Nola and Jake Arrieta at the top of the rotation, the team is relying on several unproven starters, including Nick Pivetta, Zach Eflin and Vince Velasquez. The Phillies are off to a hot start offensively, but their staff ERA is 5.09 through 11 games.

It’s not going to be easy for the Giants to part with the franchise icon, who played a major role in three World Series championships and is now in his 11th season with the team after being selected 10th overall in the 2007 MLB Draft.

But San Francisco is a team in transition, and the Giants are off to a 5-9 start after a 73-89 season in 2018. Bumgarner is arguably its best veteran trade asset, though his velocity and performance have slipped a bit over the past couple of seasons.

Morosi suggests that the Brewers could also get involved in the bidding for Bumgarner, as they are expected to have innings limits for young hurlers Freddy Peralta, Corbin Burnes and Brandon Woodruff.