The Blue Jays are more than familiar with oblique injuries. Third baseman Brett Lawrie missed time earlier in the season because of the same problem, and right-hander Brandon Morrow had trouble returning from one last year. It's the type of ailment that's hard to gauge just how long the recovery process will take.
"It's hard to say," said Blue Jays manager John Gibbons of McGowan's time table, adding that he will be completely shut down for at least the next few days. "Those things can get bad. We don't think it is, but they can drag on, too. We don't know yet."
McGowan strained his oblique while pitching to Oakland's Yoenis Cespedes but decided to remain in the game. He faced another two batters in the sixth inning and three more in the seventh.
That would normally be a cause for concern, because the Blue Jays would like to see pitchers disclose a potential injury as soon as it happens, but Gibbons is willing to cut McGowan some slack. The oft-injured reliever entered this season having appeared in just five games since 2008 because of multiple shoulder problems, a knee injury and plantar fasciitis.
There's a level of frustration for McGowan as he attempts to remain on the field for an extended period of time. He has made 16 appearances for the Blue Jays this season, allowing just four earned runs over 17 innings.
"He's different; he has been hurt so much," Gibbons said. "He's probably tired of being hurt. But you have to be smart with it because that can linger, that can turn into a long-term deal."
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.