During the fourth inning of the Arizona Diamondbacks/New York Mets game on Sunday, Arizona pitcher Jason Marquis struck Mets catcher Josh Thole with a pitch. Upon impact, both players fell down into respective heaps.

Why? It turns out that in the prior inning, Marquis' leg had been hit by a ball off the bat of Mets centerfielder Angel Pagan. The force broke the fibula bone in the pitcher's leg, but he decided to keep playing.

Apparently, Marquis didn't realize his leg had been broken. In fact, he was able to throw 13 more pitches and take an at bat, before the injury caught up with him and he was forced to leave the field.

"The pain was enough I could deal with to stay out there," Marquis told reporters after the game. He is expected to be out at least four weeks.

Watch a clip of the fall below, plus an interview with Marquis after the game:

Marquis talks about playing with a broken leg:

[via Washington Post]