Signing a pitcher in his thirties to a monster contract is a risk. But in the case of the Cubs and Jake Arrieta , it represents the lesser risk. The bigger one is assuming that Arrieta can be replaced.

The Cubs have been searching for young, controllable starting pitching for years now. They're driven by the uncertainty they'll face when Arrieta and John Lackey reach free agency after next season.

But why not pay the price to have Arrieta, Jon Lester and Kyle Hendricks under control through 2020? That would give the Cubs four more shots at championship behind the guys who started 14 of their 17 postseason games this past October. Arrieta, Lester and Hendricks were 6-3 with a 2.27 ERA over 83 1/3 postseason innings among them. They all handled the workload of long seasons and the high-stakes intensity of the World Series.

Shouldn't the Cubs do everything they can to keep them together while they have the best lineup in the Major Leagues?

Kris Bryant , Anthony Rizzo , Addison Russell , Kyle Schwarber , Javier Báez and Willson Contreras are all under the Cubs' control through 2021. Keeping Arrieta in the rotation increases the odds that those guys can become this generation's version of Derek Jeter, Bernie Williams and Jorge Posada, reaching triple digits in postseason games played.

Arrieta is a year away from free agency. His agent, Scott Boras, said at the Winter Meetings that any talk about a possible extension to keep him with the Cubs will come in January, when the sides meet to discuss Arrieta's 2017 salary (estimated at $16.8 million by MLB Trade Rumors' arbitration projections). The Cubs should view this as a critical negotiation to keep an invaluable piece of their puzzle.

What is Arrieta worth? How about $28 million a year for six years ($168 million total), with an opt-out clause after three years? I'd even go to seven years, $200 million if that was what it took.

There was a time in 2016 when Arrieta's mechanics got off and he looked mortal -- 7-6 with a 4.44 ERA in his final 16 regular-season starts, beginning on June 27 -- but he got himself locked in for the postseason and was a huge team-first player when manager Joe Maddon understandably moved him behind Lester and Hendricks in the October rotation.

While Arrieta didn't just flip a switch and go back to pitching his best in October -- the Cubs lost his starts against the Giants and Dodgers, and he finished with a 3.63 ERA in four starts -- he was rock solid in Games 2 and 6 of the World Series against the Indians (2-0, 2.38 ERA). The Cubs don't win the World Series if he blinks, but he's not the blinking kind.

Including his track record in huge October starts (like the 2015 NL Wild Card Game shutout of the Pirates), Arrieta has been the second-most dominating pitcher in the Major Leagues over the last three seasons, behind only Clayton Kershaw . He's gone 50-19 with a 2.42 ERA over 89 starts, beginning with his little noticed work for the Cubs in 2014. He's compiled a rate of 9.2 strikeouts per nine innings and a WHIP of 0.97, allowing only 10 home runs a year.

Arrieta's combined ERA+ for these three seasons is 160. That's better than the 2016 ERA+ of the two Cy Young winners ( Max Scherzer , 141; Rick Porcello , 145).

Can you really replace a guy like this?

Arrieta probably would have been signed a long time ago if he was five years younger, but he'll be entering his age-31 season in 2017 and history has not been on the side of teams handing huge contracts to pitchers in their thirties. There's a big risk in signing any pitcher to a long-term contract.

But when you look at ones that have blown up on teams, few of them belonged to pitchers who look like Arrieta -- a tall, well-conditioned right-hander.

The list of bad deals almost always starts with Mike Hampton, Barry Zito and Johan Santana -- all of whom were average to undersized left-handers. It does include an Arrieta-like guy in Matt Cain , but don't overlook two other guys a lot like Arrieta.

Scherzer and Kevin Brown were late-bloomers, like Arrieta. While Cain threw 200 innings in his age-22 season, Brown didn't reach that plateau until his age-26 season; Scherzer was in his age-28 season when he did.

Scherzer is two years into his seven-year, $210 million deal with the Nationals and showing no signs of slowing down. Brown's six-year, $105 million deal with the Dodgers is often considered to have gone bad for the team, but he was entering his age-34 season when he received it.

Beginning with his age-31 season -- where Arrieta is now -- Brown delivered an average of 5.7 WAR through his age-37 season. That seems like a reasonable projection for pitchers like Arrieta and Scherzer.

Arrieta has been open about his belief that he should be paid at the top of the scale. "Aces get seven [years],'' he said last May. He's right. That's how heavily this market values pitching. So the sooner the Cubs give him seven, the better off they'll be. A seven-year deal now is as long as a six-year deal when he hits free agency.

With major investments in Jason Heyward and Lester already on the books, can the Cubs afford to make another one with Arrieta?

Absolutely.

They did go over the luxury tax threshold in 2016 and seem unlikely to operate as repeat offenders. But having such a strong core of young players provides a window to spend heavily on pitching, wit the roster crunch not coming until 2020 or even '21. They can extend Arrieta and still afford another major investment in a player, like Shohei Ohtani, the Japanese Babe Ruth.

It's the offseason after 2020 when Hendricks will potentially have reached free agency, with Bryant and Russell positioned on the threshold and Schwarber and Baez not far behind. But Lester will be off the books, unless he's still going strong and the Cubs exercise his option for '21.

Cubs president Theo Epstein has built a powerhouse to last. It would be a shame for the club to let Arrieta walk away and wind up needing someone just like him in future Octobers.

Phil Rogers is a columnist for MLB.com.