It’s been a while since the Phillies have had to worry about the front of their starting rotation, which over the past four seasons has been anchored by co-aces Zack Wheeler and Aaron Nola, though last year it was uncertain how much longer that stability would continue: Nola became a free agent at the end of last season and Wheeler’s contract was set to expire after the 2024 campaign.

But Philadelphia acted swiftly to keep both pitchers around. After re-signing Nola before Thanksgiving, the Phillies announced on Monday that they had extended Wheeler through the 2027 season. The three-year deal is reportedly worth $126 million, and in terms of its $42 million average annual value, it is the largest extension in baseball history.

Wheeler, who turns 34 in May, has been one of the best starting pitchers in baseball since he joined the Phillies in December 2019 on a five-year, $118 million contract. Over the last four seasons, he leads the majors with 19.3 WAR. If RA9-WAR is more your style, Wheeler has the second highest mark in that span despite pitching in front of what often has been a lackluster Phillies defense behind him. He also ranks fourth among qualified starters in FIP (2.90) and innings (629.1), and 11th in ERA (3.09). Last year, he made 32 starts, allowing a 3.61 ERA and 3.15 FIP over 192 innings, enough for a spicy 5.9 WAR.

It’s hard to overstate the Wheeler’s importance to the Phillies. When he arrived, Philadelphia was better than it had been during its first five years of rebuilding, when it posted a .427 winning percentage from 2013–17, but it was still barely a .500 club. The Phillies remained stuck in neutral for Wheeler’s first two years, but their rotation improved immediately; after ranking 23rd in the majors in starting pitching WAR in 2019, Philadelphia ranked third in ’20 and fourth in ’21, a year in which Wheeler finished second in the NL Cy Young voting.

The Phillies finally broke through in 2022 and made up for lost time. That year, they won the NL pennant and came within two games of winning the World Series, and they were one win away from making a second consecutive World Series appearance last year. Wheeler has been excellent in the playoffs, too: He has a 2.42 ERA and 2.72 FIP over 11 postseason games (10 starts).

Simply, between his regular season and postseason dominance, the Phillies could not afford to risk losing Wheeler in free agency, even if that meant giving him the most lucrative per-year extension ever.

That said, ZiPS expects Wheeler to decline over the next few years, though that is more based on the inherent health risks that come with a pitcher in his mid-30s, rather than his overall ability. The computer would want to pay him about $30 million per season, but this organization, with its talented but aging core, is firmly in win-now mode. The “Stupid Money” Phillies of all teams weren’t going to let a dollars per WAR figure prevent them from extending their best pitcher.

Whether or not the Phillies win the World Series in the next several years, Wheeler and Nola will go down as one of the greatest pitching duos in team history, along with Curt Simmons and Robin Roberts, Steve Carlton and Larry Christenson, and Jim Bunning and Chris Short. Even if both head to different teams at the end of their new contracts, they still project to be in the top 10 of all-time Phillies pitchers.

At least to my eyes, there aren’t any red flags in Wheeler’s profile that the computer didn’t consider. His breakout seasons came with the Mets, but he didn’t become a true ace until he joined the Phillies. With New York, Wheeler relied on a sinker that threatened to take the hands off right-handed hitters, but he lacked the pinpoint command of the pitch that he has found in Philadelphia, where he has also added a sweeper that maddeningly looks a lot like that sinker as it approaches the plate — until it breaks in the opposite direction. With the Phillies, he has become much better at landing his curve just below the bottom of the strike zone, which has helped him against lefties. Wheeler still throws pretty hard, but he also is much more than just a grip-and-rip hurler. That should help him survive and continue to thrive when his velocity dips as he ages.

Just in case you’re not convinced at this point about the consequences of the Phils not having Wheeler, I ran a quick sim of the 2024 season using the ZiPS projections. ZiPS currently projects the Phillies to have a 56.2% chance of going to the playoffs and 14.4% odds to win the NL East. In the simulations that the Phillies fail to get 20 innings from him (about 6.2% of sims), resulting in a lot more innings from Spencer Turnbull and Mick Abel, the Phillies only made the playoffs 37.1% of the time, and their probability to win the division chopped nearly in half, to 7.6%.

With only Matt Strahm and Jeff Hoffman eligible for free agency after 2024, the front office can start addressing their next challenge, putting together enough young talent to transition the franchise to its next core of players without having to endure another interregnum of rebuilding. But, like the threat of a headache after a night of drinking, that’s a tomorrow problem. For today, keeping Wheeler in town keeps the party going.