Imanaga’s injury follows a start Tuesday in Pittsburgh in which he left in the sixth inning with leg cramps in both legs. He said he felt good Sunday before the injury, and “there was no sign in the back of my leg” before the start.

The Chicago Cubs are going to be cautious with Shota Imanaga while the left-hander recovers from his first hamstring injury.

An extended absence for Imanaga would further stress a pitching staff that has been propped up by a prodigious offense.