Matt Carpenter broke his left foot when he fouled off a pitch during the New York Yankees' win over the Seattle Mariners on Monday night.

After hobbling in pain, Carpenter was checked on by Aaron Boone but finished the at-bat and struck out swinging. He said he knew something was wrong but thought he could finish the at-bat and drive in a run.

He will be out indefinitely.

"When I went to swing on the next pitch, as soon as I started to plant and rotate on that back foot, my lower body like gave out and I wasn't able to," Carpenter explained. "Thankfully, probably the best thing that happened was to swing and miss -- because if I hit it and had to run, I might have made it worse. But I knew it wasn't good."

Carpenter is batting .305 with 15 home runs and 37 RBIs in just 128 at-bats for New York this season, and he had reached base in 27 of his 35 starts.