Jon Lester could never pick up a baseball again and the Cubs would still be satisfied with their $155 million investment. The parade down Michigan Avenue will always be worth it.

But 362 days later, Lester isn’t ready to spend all his time hunting in Georgia and playing celebrity golf events. The Cubs still absolutely need Lester’s presence and credibility. Not to prove that this franchise is serious about winning — the way his decision to sign with a last-place team after the 2014 season accelerated the rebuild — but to again anchor a rotation that might be at its most vulnerable point since those summers of flip deals.

Super-agent Scott Boras wants to keep all big-market teams in play for leverage — and Jake Arrieta is too savvy to completely rule out a return — but signs point to the Cy Young Award winner getting his nine-figure megadeal somewhere else. The expectation is John Lackey will retire and become the anti-David Ross, only popping up in Twitter photos when his family goes trick-or-treating with the Arrietas and Tommy La Stella. The farm system isn’t producing internal solutions anytime soon.

That leaves Lester, Kyle Hendricks, Jose Quintana and two giant question marks for this winter, the Cubs likely pursuing one free-agent starter (Alex Cobb?) and trading from their surplus of hitters (Ian Happ?) to get a young pitcher and continue the momentum from three straight trips to the National League Championship Series.

“Everybody involved has done nothing but deliver on their promises to me when I signed here,” Lester said, crediting by name chairman Tom Ricketts, team president Theo Epstein, general manager Jed Hoyer and manager Joe Maddon after the Los Angeles Dodgers dismantled the Cubs in the NLCS.

“I know you guys are probably sick of me by now, but I’ve got a guaranteed three more to go, so suck on that one,” Lester said, cracking up the reporters surrounding his locker inside the Wrigley Field clubhouse. “Hopefully, in those next three years, we’re able to maybe win another one or two. That’s up to these younger guys to carry my load on that one.”

Lester has credited Hendricks for the unmatched preparation that made him the Game 1 starter against the Washington Nationals in the first round of the playoffs, and raved about Quintana’s work ethic and personality since getting traded from the White Sox during the All-Star break.

But even with the blockbuster Quintana deal, the Cubs are still bracing for the possibility of replacing 40 percent of their rotation, at a time when Lester is about to turn 34 and coming off a season where he put up his lowest number of innings (180.2) since 2007 (when he was still recovering from a cancer diagnosis and lymphoma treatments). Lester’s 4.33 ERA was almost exactly the league average and his trip to the disabled list in the middle of August/early September was his first since 2011.

“Halfway through, I think we’re really happy with the first half of that deal,” Epstein said. “It’s been a really nice success for him and for us. That’s really the half of the deal that’s the key when you make those kinds of deals. If you don’t get return on the first half, you’re probably in trouble.

“You better get production in the first half of those deals — or it’s going to end up being a big mistake.”

The Cubs hope Lester can model Andy Pettitte, the left-handed pitcher he’s been compared to since coming up with the Boston Red Sox. Pettitte got some, uh, help, admitting to using human growth hormone while recovering from an elbow injury in 2002, his reputation stained in the Mitchell Report. But the overall picture of Pettitte is someone who won four World Series rings with the New York Yankees, accounted for 276-plus innings in the playoffs and started 30 times during his age-41 season.

No matter what happens from here, Lester has been worth every penny. No one else in the big leagues has made at least 30 starts in each of the last 10 seasons. He essentially averaged a strikeout per inning this season and is only a year removed from finishing second in the NL Cy Young vote.

“In Jon’s case, look, he still has all the characteristics that we think make him an effective pitcher and a reliable bet going forward,” Epstein said, “because his mechanics are still sound. His arm — he had a little bit of shoulder fatigue — but bounced back from that. Knock on wood, he’s avoided any kind of significant injury.

“He’s shown the ability to pitch — and pitch effectively — without his best stuff on certain days when he doesn’t have it. He had a few uncharacteristic really rough outings this year and was prone to the long ball more than normal.

“But besides that, he had some really nice stretches where he was sort of everything we hoped he could be. We’re counting on him to be a really big part of our pitching staff moving forward.”

The bottom line is that Lester has guts and the Cubs have faith that he will somehow figure out a way to compete. He shut down Washington for six innings in Game 2, leaving with a 2-1 lead before a bullpen meltdown at Nationals Park. He retired the first 10 Washington hitters he faced as a Game 4 reliever at Wrigley Field, a sign of how much the Cubs wanted to win that day. Three days later, he exited a 1-1 NLCS game at Dodger Stadium in the fifth inning, which will be remembered for Justin Turner’s three-run walk-off homer against Lackey.

This will be an opportunity for Lester to show even more of his personality, take on a more vocal leadership role, work with a new pitching coach (Jim Hickey) and maybe even cement his spot in the Hall of Fame with another World Series run.

“I don’t really care what people say about me on the field,” Lester said. “I may be an a------. I may show my emotions too much. I might show up the umpire too many times. I may yell at hitters. I don’t really care. But in this clubhouse — with my guys and my team — that’s what drives me.

“When I walk away from this game — just like if John Lackey walks away — (I want) everybody in this clubhouse (to) say the exact same thing: ‘That sumb---- had our back.’

“At the end of the day, man, the stats and all that other BS, that’s great. But that’s what I want. That’s what I want my guys to say about me.”