McMahon is not in the starting lineup for Monday's series opener against the Red Sox due to a jammed finger, Patrick Lyons of JustBaseball.com reports.
McMahon was originally slated for a rest day Sunday, but he was inserted into the starting lineup after Ezequiel Tovar went home with flu-like symptoms and wound up jamming his finger. The issue doesn't appear to be serious though, and McMahon could be back Tuesday. Aaron Schunk will get the nod at the hot corner and bat ninth against Boston right-hander Tanner Houck.