ARLINGTON -- The Rangers may have to put outfielder Joey Gallo on the injured list after he left Sunday’s 6-2 win over the Royals in the fifth inning with tightness in his left oblique muscle.

Gallo is scheduled to undergo an MRI to assess the extent of the injury, but manager Chris Woodward said the Rangers will treat this cautiously.

“He creates so much torque in that body, even if it’s a small oblique issue, I don’t want that to turn into a major one,” Woodward said. “He passed a lot of the strength tests, but if there is something in there, we’ll find out and plan accordingly after that.”

Gallo, who hit a two-run home run in the bottom of the fourth, first felt the muscle in the top of the fifth inning when he tried to make a throw from the outfield. Gallo mentioned the injury when he returned to the dugout for the bottom of the fifth. He was the third batter up for the Rangers.

“He said before the at-bat he didn’t think it was any kind of muscular thing,” Woodward said. “Felt like a chiropractor popped him the wrong way. He didn’t know what it was.”

Gallo fouled off a 2-1 pitch and was visited at the plate by Woodward and trainer Matt Lucero. Gallo stayed in the game for one more pitch and checked his swing on a slider in the dirt. At that point, Woodward came back out on the field and convinced Gallo to come out of the game.

“After that, first swing, we went out and talked to him. He said, ‘No, no, I’m fine … I didn’t feel anything,’” Woodward said. “Then next pitch, he felt something, and I said, ‘You’re out.’”

Gallo was replaced by Danny Santana and went to the training room for treatment. He passed the strength tests, but the Rangers still want to see the MRI results.

“I wouldn’t say he passed with flying colors,” Woodward said. “He’s so strong, he passes most strength tests even though there might be a bit of an issue there. Once we get the MRI, we’ll know what’s going on.”

Gallo missed Wednesday’s game in Seattle with a sore right wrist but started the next three games against the Royals. He hit a home run on Friday night and again on Saturday. He is now hitting .276 with 17 home runs, 41 RBIs and a .653 slugging percentage on the season.

The Rangers are 12-5 when Gallo hits a home run. They don’t want to risk losing that for an extended period of time.