TORONTO — Astros’ designated hitter Yordan Alvarez grabbed his right side and grappled several times as he rammed the visiting club at Rogers Center after losing 3-2 to the Blue Jays on Thursday. The batter left the game after his first inning with an uneasy slanted right.

It is not known the extent of the injury or how long Alvarez may be sidelined, but Astros manager Dusty Baker wasn’t entirely optimistic.

“We’ll reassess him tomorrow,” he said. “That’s a big hit right there. We just have to regroup and try to figure out how we’re going to win a few ball games and get this over with.”

Álvarez said he felt oblique pain on his last swing into the batting cage before the match and then worsened when he swung and missed twice in his first game against Jez Jose Berrios. He was out on first base and removed from the game.

Alvarez entered the game having reached base safely in 19 consecutive games and led the major leagues with 55 RBIs. He had started 36 consecutive games after missing four games due to a stiff neck.

“Yordan is an essential piece of the squad,” said shortstop Jeremy Peña. “Not only in the lineup, but in general for this team. To see him leave the game early is never a good thing.”

Astros second baseman Jose Altuve suffered a mild oblique injury on a swing on June 2 and missed the next four games. Altuve returned to the lineup on Wednesday, and the Astros can only hope Alvarez returns quickly.