HOUSTON — The Texas Rangers added right-handed starters Max Scherzer and Jon Gray to their American League Championship Series roster Sunday, fortifying their pitching staff before their first postseason matchup with the rival Houston Astros.

The addition of Scherzer, who has been out since Sept. 12 with a shoulder strain, was expected after manager Bruce Bochy said Saturday that “he’s doing really well.” The status of Gray, Bochy said, was “on the fence,” but the Rangers were confident enough after he threw Saturday to include him.

Bochy said Sunday that Gray will likely serve as a reliever given “he’s not stretched out right now” but that Scherzer will start.

We can be flexible with Game 3 and 4 with him, so if needed tonight, we could use him,” Bochy said of Scherzer.

Left-hander Jordan Montgomery and right-hander Nathan Eovaldi, who have started four of the Rangers’ five playoff games, will start Games 1 and 2.

Houston made one change to its roster, replacing outfielder Jake Meyers with right-handed reliever Ronel Blanco. The Astros did not include right-handed reliever Kendall Graveman, who is out with a shoulder issue.

Scherzer, 39, joined the Rangers in late July via a trade with the New York Mets. Texas expected him to be its top starter in the postseason after Jacob deGrom, who signed a five-year, $185 million deal with the Rangers in the offseason, needed Tommy John surgery.

“Scherz is Scherz,” Eovaldi said. “His stuff’s unbelievable. He knows exactly what he’s doing out there.”

In eight starts for Texas, Scherzer struck out 53 in 45 innings and posted a 3.20 ERA while limiting opponents to a .174/.249/.311 line. While he was thought to be out for the rest of the season at the time, the Rangers’ dominant playoff run — sweeping the 99-win Tampa Bay Rays in the wild-card series and winning three straight to oust top-seeded Baltimore in the division series — allowed him enough time to heal.

Gray hit the injured list Sept. 25 with right forearm tightness after starting 29 games in which he threw 157⅓ innings with a 4.12 ERA. The 31-year-old signed a four-year, $56 million deal with the Rangers before the 2022 season, the same year in which they started their rebuild by guaranteeing $500 million to free agent shortstop Corey Seager and second baseman Marcus Semien.

Texas led the AL West for most of the year, but Houston won the division title via tiebreak on the final day of the regular season. Both teams finished with 90 wins, as did the Philadelphia Phillies, who will face the 84-win Arizona Diamondbacks in the National League Championship Series.

The Rangers are now at full strength after a spate of injuries hindered them toward the end of the regular season. Three All-Stars — catcher Jonah Heim, right fielder Adolis Garcia and rookie third baseman Josh Jung — missed significant time that, along with the injuries to Scherzer and Gray, hampered the Rangers down the stretch.

Montgomery, who was acquired from the St. Louis Cardinals at the trade deadline and will start Game 1 against Houston’s Justin Verlander on Sunday, stepped into the ace role and has thrived. In 11 starts for the Rangers, he had a 2.79 ERA, and he followed seven innings of shutout ball in his Rangers playoff debut with a four-inning, four-earned-run outing in an 11-8 win over Baltimore in Game 2.

Eovaldi has been even better this postseason, allowing one run in each of his starts: 6⅔ innings in the clincher against Tampa Bay and seven innings in the Game 3 that ended the 101-win Orioles’ season.

Scherzer, the three-time Cy Young Award winner who is 7-7 with a 3.58 ERA in 27 career postseason games, could slot into the Game 3 — and potentially Game 7 — role for the Rangers in the ALCS. Scherzer’s last postseason outings against the Astros were in 2019, when he started Games 1 and 7 of the 2019 World Series.

Bochy could use Gray as the No. 4 starter and move Dane Dunning, who has alternated between a starting and relief role, back to the bullpen, which has been a strength for the Rangers in October despite concerns about it entering the month.

To make room for Scherzer and Gray, the Rangers removed left-hander Brock Burke and right-hander Matt Bush from the roster.