HOUSTON -- If a second consecutive loss to the A’s on Wednesday night -- and third in a row overall -- wasn’t enough to leave the Astros discouraged, an injury to star second baseman Jose Altuve likely did the job.

Altuve was removed from the game with right side discomfort, which he suffered swinging the bat in the fifth inning, and later said he doesn’t think it’s serious. He left the game moments before the A’s rallied for three runs in the sixth to send the Astros to a 5-4 defeat at Minute Maid Park.

“I’m not really concerned right now, which is good,” Astros manager Joe Espada said.

The Astros have a 3 1/2-game lead over the Mariners atop the American League West.

While leading off the fifth inning, Altuve stepped away from the plate after fouling a ball and motioned to the dugout. Espada and head athletic trainer Jeremiah Randall came onto the field to check on Altuve, who stayed in the game for one more pitch. He struck out on a foul bunt and was removed to start the sixth.

“He got fooled on that pitch and kind of felt something,” Espada said. “Out of precaution, he decided to bunt with two strikes just to make sure he was fine. Right now, he’s day to day.”

Altuve, who missed a few weeks last season with a left oblique strain, said he felt something on his right side, but he didn’t draw any correlations to an oblique injury like the one he had last July.

“Sometimes you have to wait until the next day and see how you feel,” he said.

The Astros are already walking a delicate balance with their lineup with third baseman Alex Bregman unable to play every day because of elbow inflammation and All-Star right fielder Kyle Tucker still working his way back into everyday shape after missing over three months with a right shin contusion.

If Altuve is unable to play for any length of time, the Astros can plug in super utility player Mauricio Dubón, who started 66 games at second base last year. Dubón won the American League Gold Glove for the utility position.

What’s more, the club announced postgame Wednesday that outfielder Chas McCormick was headed to the injured list with a small fracture in his right hand. He’s expected to return by the end of the season.

“I’m not really worried,” Altuve said. “Maybe I just wake up tomorrow and I’m good to go. I don’t really want to make any decisions tonight because normally with an injury, you wait until the next day and see how you feel.”

Trailing 3-2 in the sixth, the A’s got a two-run homer from Kyle McCann to score Jacob Wilson and take the lead, and they chased starter Hunter Brown when Max Schuemann followed with a double. He later scored as Oakland tagged Brown for five runs on nine hits and one walk with seven strikeouts in five-plus innings of work.

“I thought they just kind of beat me tonight, especially in the sixth inning there,” Brown said. “I thought I made a really good pitch to Wilson, and he was able to send it out there to left field. And then I probably missed my spot by 20 inches to McCann. Anything that goes up in the air to left field, you get a little worried, and that one took off. I coughed up the lead for the second time in the game. That was tough.”

The Astros have lost six of their past eight games, with five of the six losses coming to teams that are under .500. That’s not ideal for a club trying to stave off the Mariners in the division race, but the A’s have a better record since the All-Star break (27-21) than Astros (27-22).

“I know they’re good,” Brown said. “I think we know they’re good. They do some things as a team that are tough, kind of across the lineup. From the top to the bottom, they can all do some different things. Coming in, I knew I was going to have to compete tonight. If you go back to my last outing against them in Oakland [on July 24], I was able to navigate eight or nine hits against them, and kind of the same thing happened tonight, but I wasn't able to keep it to a minimum. They were able to cash in.”