Kyle Schwarber's time with the Boston Red Sox may be coming to an end.

The slugger had a mutual option on his contract for the 2022 season that ESPN reported was worth $11.5 million with a $3 million buyout, but he declined his option on Thursday.

However, he could still return to the Red Sox as a free agent.

Boston acquired Schwarber via trade from the Washington Nationals in July, and he proceeded to help lead it to the American League Championship Series. He slashed .205/.286/.432 with three home runs and six RBI in 11 postseason games. 

While the option wasn't exercised, Schwarber thrived during his brief time with the American League East team in 2021.

He slashed .291/.435/.522 with seven home runs in 41 regular season games, which is a far cry from the .188 batting average he posted for the Chicago Cubs during the 2020 campaign before the team he played his first six years with non-tendered him heading into 2021.

Washington signed him to the one-year deal that featured a rather uncommon mutual option for 2022, and he also showed drastic improvement for the Nationals.

"I knew 2020 wasn't a representation of me," Schwarber said, per John Tomase of NBC Sports. "I just knew that I was better than I performed. It's no excuse. I didn't do it. It is what it is, and I got DFA'd. Going into the offseason, I was more worried about going out there and knowing that I'm better than what I did last year. It's been a good year so far, but there are still things to accomplish, playoffs and everything else. I'm a big proponent that you're never a complete player, you just keep learning and learning and learning."

Schwarber launched 25 home runs while hitting .253 in 72 games with the Nationals before they traded him to Boston.

That was much more in line with his more productive years on the Cubs when he cemented himself as a fan favorite while hitting a combined 94 home runs from 2017 through 2019 after he was already a franchise hero because of his 2016 efforts.

Despite tearing his ACL and LCL during an April game of that season, he returned in time for the Cubs' World Series appearance against Cleveland and played their four road games as the designated hitter.

All he did was hit .412 in the series and help Chicago snap a championship drought that dated back to 1908.

Schwarber is now a free agent and will surely draw interest as someone with power and a track record of postseason success.