The Texas Rangers need additions, not subtractions headed into the heart of August. So far, the latter are the only ones filling in these days.

Fresh off a 7-2 home loss in Sunday’s finale against the Boston Red Sox, the Rangers enter what could be a make-or-break 13-game stretch against four contending American League playoff teams. They welcome rival the Houston Astros for a three-game homestand before traveling to the East Coast with matchups against the New York Yankees and Boston Red Sox.

They’ll close out the run with a four-game battle against the Minnesota Twins in Arlington.

If the season ended on Sunday, New York and Minnesota would be in the postseason as wild-card squads. Houston, which remains a game out of first place in the AL West, would miss a wild-card spot by five games. Boston would be on the outside looking in by a 2.5-game differential.

While Max Scherzer and Jon Gray are out, Tyler Mahle is in. Mahle, the right-hander who signed a two-year deal this offseason, is nearing his debut with the defending champs after recovering from Tommy John surgery. He’s made six starts in the minors, which equals one more than during his final season in Minnesota.

In three Triple-A starts, Mahle boasts a 1.93 ERA to match his eight strikeouts. He’s issued two walks and has batters hitting .193 in 8 1/3 innings.

That’s the version Texas needs entering a crucial part of the season. The Rangers signed him to help out in a run for October, and now, it’s a race to the finish line.

While Texas dropped the series against Boston, Houston lost two of three to Tampa. And Seattle might have won the series of Philadelphia, but its inconsistencies at the plate still leaves a gap to make up for lost time.

Andrew Heaney takes the mound Monday night at Globe Life. After that, manager Bruce Bochy expects Mahle to hit the rubber Tuesday night in Game 2 of the Lone Star Series. How will he fare? Bochy said he’s “good to go” after watching his fastball reach 94.8 mph during the series against Sugar Land.

Initially, four quality innings might have been enough to call his first start promising. With Cody Bradford potentially moving into the rotation, the 29-year-old might need to last a bit longer to save the bullpen.