(CBS) Cubs right-hander Jake Arrieta left Monday’s start in Pittsburgh after experiencing pain in the back of his right leg. The team announced Arrieta was being evaluated for what’s either cramping or a more serious hamstring injury.

Arrieta left with one out in the third inning of the Labor Day matinee with the Pirates after a pitch to Josh Bell sailed off while pain appeared to set in. After team trainers went out to visit, Arrieta attempted to throw a warm-up pitch but experienced too much pain to push off the mound.

The status of Arrieta will be updated after the game, which the Cubs trailed 3-0 after losing Arrieta. Reliever Justin Grimm entered for Arrieta.

The Cubs have experienced poor fortunes with the health of their starting pitching this season. Jon Lester recently returned from a two-week stint on the disabled list, Kyle Hendricks missed much of June and July and John Lackey also has had a stint on the DL.

Now, the Cubs are hoping that Arrieta was only experiencing cramping.

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