Masterson strained his left oblique against the Baltimore Orioles on Sept. 2. Oblique injuries often sideline players for at least one month, but Masterson still hopes to return before the end of the regular season.
The starter discussed his injury with Hoynes, stating:
"I still don't know what the exact timetable is, but we're moving in the right direction. We've got a baseball in our hand."
Masterson has been Cleveland's best starter in 2013, leading the team in starts, innings pitched and strikeouts. Overall, he is 14-10 on the year with a 3.52 ERA.
The Indians enter Friday with a 78-68 record, 1 1/2 games behind the Tampa Bay Rays for the second AL Wild Card spot. Cleveland has a favorable schedule down the stretch, with only three remaining games against teams above .500.