Arizona Diamondbacks free agent pitcher Zac Gallen’s projected free agent market has been tricky to pin down.
The 30-year-old Scott Boras client had been one of the seven most valuable pitchers in baseball from 2022-24 using FanGraphs WAR, but he entered the market coming off his career worst major league season in 2025.
Gallen produced a 3.29 ERA from 2019-24, but he turned in a 4.83 ERA campaign with increases in walks and home runs this past season. He finished strong with a 3.32 ERA over the final two months of the year, showing improved command.
The Diamondbacks extended the qualifying offer to Gallen, which he is expected to decline, meaning other interested teams would have to part with draft capital to sign him.
National outlets differ on his market, from long-term contracts to two-year prove-it deals that may include an opt-out to try again:
Zac Gallen contract projections
ESPN: 4 years, $76 million
The Athletic’s Tim Britton: 2 years, $42 million
The Athletic’s Jim Bowden: 5 years, $135 million
Spotrac: 4 years, $74.9 million
MLB Trade Rumors: 4 years, $80 million
The constant here is that his salary is expected to be around $20 million per season, close to the $22 million QO — aside from Bowden’s optimistic outlook.
There are many teams with starting pitching needs, the Diamondbacks included. Gallen hitting free agency after they traded Merrill Kelly in his walk year opened two spots in the starting rotation. Corbin Burnes will not be back for the first half of next year, at least, as he rehabs from Tommy John surgery.
The free agent starting pitcher class is headlined by Framber Valdez and Ranger Suarez. Gallen, Kelly, Tatsuya Imai from Japan, Dylan Cease, Shota Imanaga, Justin Verlander, Michael King and Lucas Giolito are other notable names who will dictate the market.
In terms of teams floated as potential fits for Gallen, the Diamondbacks logically came up. He expressed his appreciation for the organization after the season and was open to coming back if an agreement could be made.
The Diamondbacks have been bigger spenders than usual over the past two offseasons, but the payroll is expected to come down some this winter. Their payroll is projected at $144 million by FanGraphs (including arbitration and pre-arbitration salaries) before they add anyone. The payroll reached a team record-high $188 million last year. Do they have $30 million to work with, or is it less? Having an expensive injured list with Burnes and Lourdes Gurriel Jr. applies pressure on resources.
The D-backs have several holes to address, such as starting pitching, bullpen, first base and outfield.
Other clubs mentioned by the aforementioned five evaluators as fits for Gallen were the Mets, Cubs, Giants, Angels, Red Sox and Astros.
Zac Gallen hits the open market this winter, after making 33 starts this year with the D-backs!#MLBNHotStove lists a few potential fits for the free agent RHP. pic.twitter.com/puZXYNXFSi
— MLB Network (@MLBNetwork) November 9, 2025
The Mets are coming off a season in which they had a top-10 offense with a top-two payroll but missed the postseason. With deep pockets and questions in the rotation, pitching is a priority this winter, and Gallen has pitched well in New York (29.2 innings, 11 earned runs and 49 strikeouts at Citi Field and Yankee Stadium). Gallen grew up in New Jersey, close to Philadelphia.
The Red Sox are another club looking to make a jump after their American League Wild Card Series loss to the Yankees. Boston was reportedly interested in Gallen ahead of the trade deadline.
Zac Gallen on free agency: pic.twitter.com/SXYXUES4f6
— Alex Weiner (@alexjweiner) September 29, 2025
What about Merrill Kelly?
The Diamondbacks parted with Kelly after 6.5 seasons at the trade deadline for three prospects, knowing he was about to hit free agency. Kelly has been open about welcoming a return to Arizona, and outlets have continued to link the two sides.
Kelly made 32 starts last season with a 3.52 ERA, finishing the campaign on the Rangers.
All five previously mentioned evaluators predicted Kelly would land a two-year deal worth between $30-46 million.
Other potential fits brought up have been the Astros, Mets, Padres, Giants, Angels and Rangers.
