CHICAGO -- The Cubs took the expected step of declining Jon Lester's option for the 2021 season on Friday. While that decision makes the veteran left-hander a free agent, the door is still open to keep him on the North Side.

Lester's option for next season was worth $21 million, but the Cubs opted instead to pay the $10 million buyout that was included in his six-year, $155 million contract. With rotation needs this offseason, retaining Lester on a restructured deal is something Chicago will undoubtedly explore.

"It remains to be seen whether Jon has pitched his last game as a Cub or not," Cubs president of baseball operations Theo Epstein said at the end of the season. "There's certainly the possibility that he continues to call Wrigley Field home.

"But, whether he leaves or stays, this is an appropriate time just to acknowledge the profound impact that he had on our organization."

The Cubs added Lester to the fold prior to the 2015 season, helping move the franchise out of rebuilding and into one of the great eras in team history. Over the past six years, Chicago reached the postseason five times, won three National League Central titles and won the World Series in '16.

Lester went 19-5 with a 2.44 ERA in 2016, finishing as the runner-up for the National League Cy Young Award. The lefty then spun a 2.02 ERA in the '16 playoffs, working three innings in the Game 7 triumph over Cleveland in the World Series. He shared the '16 NL Championship Series MVP honors with Javier B¨¢ez.

"This was the guy we're going to bring in to change the culture of the Chicago Cubs," outfielder Kyle Schwarber said in September. "And, I mean, I think it's been pretty successful since he's come here.

"We all don't know what the future holds for him. I hope it's another year with the Chicago Cubs. But I think he should be really proud of what he brought to this organization."

There is certainly a sense of unfinished business for Lester, who was lined up to start Game 3 of the NL Wild Card Series before Miami swept the Cubs in two games. There is not only the goal of bringing another World Series to the North Side, but Lester is sitting seven wins shy of 200 in his career.

This past season, Lester surpassed 1,000 innings with the Cubs and ended with a 3-3 record and 5.16 ERA in 12 starts. In his Cubs career, the 36-year-old has gone 77-44 with a 3.64 ERA in 171 games. He was an All-Star in 2016 and '18, and he turned in a 2.44 ERA in 70 postseason innings for Chicago.

"If this is it here, this is it. I have to move on with it," Lester said near the end of the season. "I've definitely appreciated everything that this organization has done for me, and I hope it's not [the end]. I hope we can figure something out for next year and these conversations are kind of null and void."

As things currently stand, the Cubs' rotation has a solid one-two combination at the top in Yu Darvish and Kyle Hendricks. Alec Mills and Adbert Alzolay give the team two more internal options, but Chicago has three free-agent starters in Tyler Chatwood, Jos¨¦ Quintana and Lester.

At the end of the season, Epstein emphasized that adding a Major League starter, plus rotation depth, was going to be a priority for the team this offseason. Maybe there is still a way to fit Lester into the 2021 puzzle. If not, he left an incredible mark on the franchise.

"We owe him a great debt of gratitude," Epstein said. "We were investing in Jon Lester the person every bit as much as we were investing in Jon Lester the pitcher. And he came through in both areas for us in typical Jon Lester fashion.

"So, huge tip of the cap to him, He's made a huge impact on Chicago Cubs baseball, and it remains to be seen what the future holds."

Cubs claim Schrock from Cards
The Cubs added some infield depth on Friday by claiming Max Schrock off waivers from St. Louis. Schrock, 26, appeared in just 11 games in 2020, filling in at second and third base for St. Louis. The left-handed-hitting infielder went just 3-for-17 with a homer (hit against the Cubs). At Triple-A Memphis in '19, Schrock hit .275/.366/.381 with two homers, 20 doubles, 12 steals and 37 walks against 49 strikeouts in 85 games. Also on Friday, the Cubs sent left-hander Rex Brothers outright to Triple-A Iowa.