New York Yankees first baseman Mark Teixeira will miss at least one to two weeks with a Grade 1 strain of his left calf, an injury he suffered while running out a foul grounder in the fourth inning Monday night.

Teixeira drew a walk in the at-bat and scored later in the inning, but he left the game after the fourth, going to a local hospital for an MRI.

"I took the first step out of the box and felt something kind of grab," Teixeira said. "I thought I could run through it, finish the at-bat. I drew the walk. Instead of loosening up as I was running, it tightened up more. I knew something wasn't right. It was severe enough that I knew I needed to get out of the game."

Teixeira is unlikely to land on the disabled list, as rosters are set to expand Saturday when the calendar turns to September. Although Teixeira hopes to miss no more than two weeks, the Yankees were without Derek Jeter for three weeks last summer with the same injury.

"It could be seven days, could be two weeks," Teixeira said, taking a best-case approach. "The MRI showed a Grade 1; it's not a Grade 2, which is a month or more. That would be worrisome. We just have to take care of it. If it's a week, great. If it's two weeks, not as great, but I'd still have plenty of season left."

The Yankees traded for Astros first baseman/outfielder Steve Pearce earlier Monday, adding a right-handed bat to their bench. Nick Swisher figures to see most of the time at first base while Teixeira is out, while Ichiro Suzuki would move over to right field, leaving left field duties to Raul Ibanez and Andruw Jones.

"We've lost a lot of people in the course of this year, so if unfortunately he's out, then someone else is going to have to do the job," Jeter said after the Yankees' 8-7, 11-inning loss to the Toronto Blue Jays. "That's basically what you have to do all year long, and we have to do it again."