CHICAGO -- Jake Arrieta was one of the most dominant arms in baseball when he helped the Cubs end a championship drought spanning more than a century. Now, the veteran pitcher is reuniting with his old club for another ride with the remaining core.

The Cubs on Wednesday officially announced a one-year contract with Arrieta. The deal includes a $4 million base salary plus incentives for 2021, and its mutual option is valued at $10 million (or a $2 million buyout), a source told MLB.com.

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"I think Jake feels like he's got something to prove," manager David Ross said via Zoom on Wednesday. "I think he's really comfortable here in this Cubs uniform and has got a long-standing history. I've watched him perform at his best and I know him. He's trying to get back to that version, or as close as he can to that in his work."

In a corresponding move, the club placed left-hander Kyle Ryan on the COVID-19-related injured list.

Arrieta immediately injects veteran experience and brings an edge to a Chicago rotation that projects to feature Kyle Hendricks, Zach Davies, Trevor Williams and Alec Mills. Right-hander Adbert Alzolay will also be competing for rotation innings both in Spring Training and during the season.

The starting staff underwent a makeover this offseason, with veterans Jon Lester, José Quintana and Tyler Chatwood being allowed to exit via free agency, and the Cubs swinging a stunning trade that shipped Yu Darvish to the Padres for Davies and a quartet of young prospects.

New president of baseball operations Jed Hoyer said via Zoom on Tuesday that the decision not to reunite with Lester -- who signed a one-year contract with the Nationals on Jan. 27 -- was more of a timing issue than anything else. Hoyer said the front office was granted permission to expand its 2021 payroll parameters after Lester wanted to finalize his decision.

"Listen, Jon Lester's been sort of almost a constant in my career," Hoyer said. "I love having him. He's an A+ teammate and obviously an A+ competitor, and I wish him luck in Washington. But that was really more of a timing issue than it was a desire issue for us to bring him back."

Hoyer has made it clear that his goal for 2021 is to balance competing in the present with planning for the future. The latter is where the Darvish trade factors into the equation. Chicago has attempted to address the former with the recent signing of slugger Joc Pederson and this latest move to add Arrieta, who brings with him the kind of experience and leadership that left with Lester.

"We've got guys with good resumes on our staff," Ross said. "But [Arrieta has] definitely got the hardware to back that up. That's what I know he'll bring. He already has that presence. I got to talk to the pitchers today and just staring into that group and then locking eyes with him, it was a nice sight from the manager's seat, that's for sure."

Back in 2015, when Arrieta cruised to stardom and helped pull the Cubs out of a rebuild and into World Series contention, the core group of Javier Báez, Kris Bryant, Willson Contreras, Anthony Rizzo and Co. were a pack of talented, green baseball kids. Now, they are veterans chasing another ring and approaching free agency.

Báez, Bryant and Rizzo can all hit the open market as soon as next winter, with Contreras following suit after 2022. Kyle Schwarber -- a key part of the core -- was non-tendered earlier this offseason. Lester, who was the leader of the room and rotation, joined Schwarber as free-agent signings in Washington.

Arrieta, who will turn 35 on March 6, was a free agent this winter following a three-year, $75 million pact inked with the Phillies. Prior to the 2018 season, the Cubs did not re-sign the righty, opting instead to pursue and sign Darvish to his six-year, $126 million deal.

Over the past three years in Philadelphia, Arrieta went 22-23 with a 4.36 ERA in 64 appearances. That includes going 4-4 with a 5.08 ERA in nine starts during the abbreviated 2020 campaign. Last year, Arrieta struck out 32 and walked 16 in 44 1/3 innings.

That was a far cry from the sheer dominance on display in 2015, when Arrieta captured the National League Cy Young Award with 22 wins, a 1.77 ERA (including a 0.75 ERA in the second half) and 236 strikeouts vs. 48 walks in 229 innings.

Arrieta famously spun a shutout in the NL Wild Card Game in the 2015 postseason, announcing the Cubs' presence on the October stage. One year later, he started Games 2 and 6 in the World Series against Cleveland, helping the Cubs end their 108-year drought.

As it happens, Arrieta remains the last pitcher to win a playoff game for the Cubs, doing so in Game 4 of the 2017 NL Championship Series against the Dodgers. Chicago lost that series in Game 5 and has gone 0-3 in its two tastes of the postseason in the past three years.

"He's got the awards. He's got the ring," Ross said. "I mean, what I saw him do in that Wild Card Game in Pittsburgh is as dominant of a performance in as much pressure as I think I've ever seen anybody under. So, this guy's been battle-tested. He's got the mentality. He's got the poise."

The Cubs pulled off a transactional heist when they landed Arrieta (along with reliever Pedro Strop) in a July 2, 2013, trade with the Orioles. The righty went 68-31 with a 2.73 ERA in parts of five seasons for the Cubs, authoring a pair of no-hitters (Aug. 30, 2015, at Dodgers and April 21, 2016, at Reds).

No, Arrieta is not the same pitcher he was back then for the Cubs. The fastball does not have as much velocity and the right-hander has started to work in a changeup more often than in the past. And throughout all the adjusting, Arrieta has still managed to keep his ground-ball rate north of 51 percent.

With plenty of innings to offer, rotation depth needed and the pile of uncertainty facing the Cubs after the 2021 campaign, a reunion with Arrieta made a heap of sense for the North Siders.

"It was really cool seeing him," Hendricks said on Wednesday. "It was like no time ever passed. I don't know where those three years went, but it was almost like he never left. Me and him have had that awesome relationship since Day One. He kind of took me under his wing when I first came up to the big leagues, taught me a lot about being a pro."