Cliff Lee is complaining about back discomfort.

Rangers assistant general manager Thad Levine said tests revealed no structural damage and that the issue was muscular. Lee received a trigger point injection, which the club hopes will calm the area down and allow him to stay on track.

The Rangers want to see how Lee reacts to his next bullpen session before determining if he can make his next scheduled start Monday at Toronto.

An injury would certainly explain his poor performance of late.