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SAN DIEGO — Suddenly, in the middle of the night on the East Coast, construction on the Chicago Cubs’ roster dramatically blew past the construction that is remodeling Wrigley Field.

Ace free agent Jon Lester is a Cub.

Your move, outfield bleachers in Wrigley Field.

News of Lester’s six-year, $155 million deal—terms confirmed by Bleacher Report sources late Tuesday night—sent the lobby buzz into overdrive here at the winter meetings and sent the Boston Red Sox sprinting toward Plan B, or Plan 1A, or whatever backup plan the pitching-desperate club can cobble together.

In Chicago, the spotlight on a week of stunning baseball news swung back where it started just days after the World Series: to the North Side, where new manager Joe Maddon already has proclaimed that he will start preaching playoffs and World Series to his group of young Cubs this spring.

With Lester wearing a Cubs uniform, Maddon’s message to a clubhouse full of young phenoms like Anthony Rizzo, Starlin Castro, Javier Baez, Jorge Soler and Kris Bryant should ring far truer than he ever could have imagined when he took this job last month.

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“It definitely makes it more believable to everybody in that room, and that’s a good thing,” Maddon said late Tuesday night as word of the Cubs’ late-night conquest spread rapidly throughout the Grand Hyatt. “Because I’ll stand up and make the same speech regardless. But when you have it backed up by that particular kind of presence, it adds to it.

“I can’t deny any of that. I’m very pragmatic. I can’t deny things. Having people like that in the room definitely benefits or helps the other guys believe this is possible.”

As Maddon spoke in the lobby just before 11 p.m. local time, the crowd around him swelled more quickly than a horde of kids around an ice cream truck. Maddon was finishing a late dinner about 30 minutes prior when he received a text from the club telling him Lester was done.

Then, he walked into a scene he never could have imagined with the cash-poor Tampa Bay Rays.

“I’ve not been on this side since my days with the Angels when I got an email that we had signed Vladimir Guerrero,” Maddon said, referring to his days as a coach on Los Angeles manager Mike Scioscia’s staff. “I was in Italy. I had to utilize the computer at the little hotel, and it said that the Angels had signed Vladimir Guerrero.”

That was in December 2004, when Guerrero signed with the Angels for five years and $70 million.

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Those were the same dollars the Red Sox used in what was widely considered a lowball offer to extend Lester last spring, a deal worth $70 million over four years. Him declining that led to the July trade to Oakland and, ultimately, severed for good a return path to Boston.

Given the new and growing buzz surrounding the Cubs, a ballpark that saw steadily declining attendance for a club that lost 286 games over the past three seasons surely will see its new outfield bleachers more crowded than the air space around the Cubs' new manager late Tuesday night as a new era begins.

“It’s really exciting to be in this position right now,” Maddon said. “I’m working with a new group of people in a very vibrant city and a great group of core players.

“And all of a sudden you add this kind of a piece to that particular puzzle. It’s very exciting.”

Though the biggest by far, Lester, 30, is not the only move this week for a Cubs organization that clearly has identified 2015 as the opening of a window toward which president Theo Epstein has been building since leaving the Red Sox after the 2011 season.

On Monday, the Cubs re-signed pitcher Jason Hammel for two years and $18 million.

On Tuesday afternoon, they acquired left-handed-hitting catcher Miguel Montero from the Arizona Diamondbacks after failing earlier this winter to sign Russell Martin. (He picked Toronto instead.)

And Tuesday night, they struck gold.

Marcio Jose Sanchez/Associated Press

Lester, one of the game’s few true aces, went 16-11 with a 2.46 ERA over 32 combined starts for Boston and Oakland last summer and has a career ERA of 3.58 over nine big league seasons.

He has earned two World Series rings with the Red Sox, winning in 2007 and 2013. Surely, just like Epstein, who was the general manager in Boston for much of Lester’s career there, he comes to Chicago envisioning what it would be like to be part of a group that wins the Cubs’ first World Series title since 1908, more than a century ago.

“I wouldn’t doubt it,” Maddon said. “I wouldn’t doubt that at all. He’s been there before. He knows what it feels like. I want to believe that he could perceive the same thing happening here.

“You’re going to have to talk to him specifically, but from my perspective, it’s exciting to be involved in this moment, and I’m eager to see what he has to say in why he chose us. And, after that, start formulating the plan for the season.”

Nowhere will the optimism and anticipation soar higher this spring than in Mesa, Arizona, where the Joe Maddon era will begin.

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Or is it the Jon Lester era?

The Red Sox now are left scrambling to fill a B-list rotation after shelling out $183 million combined last month to sign free-agent sluggers Pablo Sandoval and Hanley Ramirez. With Clay Buchholz currently their top starter, it’s like installing a Ford Pinto engine into a Lexus.

Likely, the Red Sox now will pursue free-agent starter James Shields. Surely, they will dive into trade talks with the Philadelphia Phillies (Cole Hamels) or the Cincinnati Reds (Johnny Cueto) or the Washington Nationals (Jordan Zimmermann, Doug Fister) or the San Diego Padres (Ian Kennedy, Andrew Cashner). General manager Ben Cherington told Boston reporters Tuesday that the club would work through "15 to 20 starting pitching scenarios” if it failed to land Lester.

As for the Cubs, they’ve got prospects that need to prove themselves. But a skyscraper like Lester atop the rotation provides plenty of shade and cover as they grow. He provides a lethal weapon for a contender.

Forget those thoughts that it will be a couple of years until the Cubs are ready to contend. That timetable just got jump-started, pronto.

“I think it definitely sends that message about how Theo and the group feels about this particular group,” Maddon said. “But understand, we have a lot of young players that have to grow up, and we have to do a good job of nurturing that and making it happen as quickly as possible.

“Having Jon there definitely adds to the flavor and the believability.”

And the pressure.

Maddon grinned. Oh yes he did.

“Never permit the pressure to exceed the pleasure,” he said, eyes twinkling. “Never.”

Scott Miller covers Major League Baseball as a national columnist for Bleacher Report. He has over two decades of experience covering MLB, including 14 years as a national baseball columnist at CBSSports.com.

Follow Scott on Twitter and talk baseball @ScottMillerBbl.