Chapman was originally injured on July 6 before a game against the Milwaukee Brewers. He insists the injury will not affect the way he pitches.
"I'm not 100 percent ready to run full speed," Chapman said, via MLB.com. "I kind of hesitated a little bit and I just kind of took it easy to go to first."
Chapman has made five regular-season appearances since July 6 and has struck out 13 of the 18 batters he has faced, allowing no runs in that time. He is 0-2 this season with 21 saves in 23 chances, a 2.12 ERA and 60 strikeouts in just 29.2 innings.
"I will be fine," Chapman said. "I've been pitching through it for a while. As long as I don't have to run, it feels good to pitch."
The Cuba native missed the first month-plus of the season after he was hit in the face by a line drive during a spring training game against the Kansas City Royals in March.