Left-hander Jordan Montgomery and the Arizona Diamondbacks are in agreement on a one-year, $25 million contract that includes a vesting player option for a second season, sources told ESPN on Tuesday night, bolstering the National League champions' rotation with the postseason standout from the team that beat them in the World Series.

The deal, which is pending a physical, ends Montgomery's free agency two days before Opening Day and could include a second-year player option at $20 million if Montgomery makes 10 starts. The option would be for $22.5 million if Montgomery reaches 18 starts and $25 million at 23 starts, sources said.

After entering the winter with hopes of a nine-figure deal, the 31-year-old Montgomery signed for a fraction of that, a coup for a Diamondbacks team whose big offseason acquisition, Eduardo Rodriguez, hit the injured list this week with a lat strain. Montgomery will join a rotation that includes top starters Zac Gallen and Merrill Kelly, along with 25-year-old Brandon Pfaadt.

Montgomery's market figured to be robust after a tremendous season in which he posted a career-best 3.20 ERA over 188 innings, the final 67 of which came with the Texas Rangers following a deadline trade from St. Louis. He continued his excellence in the postseason, tossing seven shutout innings in the wild-card round against Tampa Bay and chasing that with 14 brilliant innings in the American League Championship Series.

Instead, Montgomery's fortunes mirrored those of three other top-end clients of his agent, Scott Boras. Outfielder/first baseman Cody Bellinger, who sought in excess of $150 million, signed with the Chicago Cubs for $80 million over three years. National League Cy Young winner Blake Snell received a two-year, $62 million deal from San Francisco after targeting $150 million-plus. He joined third baseman Matt Chapman, who wanted nine figures but got three years and $54 million, in San Francisco.

Like all three of them, who received opt-outs after the first year of their deals, Montgomery will control whether he hits free agency in a loaded class of 2024-25. The disappointment of the guarantee is buttressed by joining a Diamondbacks team that heads into 2024 in far better shape than last year as it prepares to take on the much-improved Los Angeles Dodgers and Giants, plus the San Diego Padres.

Montgomery is the latest acquisition in a busy winter for Arizona, whose payroll will balloon to a franchise-record $168 million. In addition to Montgomery and Rodriguez, the Diamondbacks re-signed left fielder Lourdes Gurriel Jr. and outfielders Joc Pederson and Randal Grichuk. They also traded for third baseman Eugenio Suarez.

The best player of them all is Montgomery, who is joining his fourth team since the New York Yankees -- with whom he spent the first six seasons of his career -- dealt him to St. Louis at the 2022 deadline. A reliable innings-eater who has topped 30 starts in three consecutive seasons, Montgomery has a career 38-34 record with a 3.68 ERA and 705 strikeouts in 755 innings after New York chose him out of the University of South Carolina in the fourth round of the 2014 draft.

Featuring a sinking fastball and a hard curve nicknamed the Death Ball, Montgomery carved through the Houston Astros in the ALCS before allowing four runs in six innings in a Game 2 loss to the Diamondbacks. It was the only game the Rangers dropped en route to their first World Series win, and there was mutual interest in a return.

But Texas' uncertainty over its local television rights tightened the Rangers' purse strings, forcing Montgomery to explore other options. Discussions with the Boston Red Sox never advanced past the early stages, nor did talks with the Yankees. The Giants at one point were a suitor but dropped out after signing Snell. Only recently did the Diamondbacks emerge as a possible landing spot.

It's an ideal landing spot for Montgomery, whose data-driven approach aligns with that of Diamondbacks pitching coach Brent Strom and pitching strategist Dan Haren. And if he can help Arizona in October the same way he did the Rangers last season, the Diamondbacks could once again surprise an NL in which the Dodgers and Atlanta Braves are favorites to win the pennant.