KANSAS CITY -- Rangers pitcher Cliff Lee was sent back to Texas on Tuesday to have his sore lower back examined by Dr. Keith Meister. Lee brought the problem to the Rangers' attention following Tuesday's 10-9 loss to the Royals.

Meister told the Rangers it was just some muscular pain and inflammation and gave Lee an injection to help alleviate the discomfort. Lee will rejoin the Rangers on Friday in Minnesota.

"Meister did not seem to think it was too serious," Rangers assistant general manager Thad Levine said. "He thinks the injection will give him a lot of relief."

Lee is scheduled to pitch Tuesday against the Blue Jays. The Rangers were already planning to push him back an extra day and let Tommy Hunter pitch on his normal four days' rest. Right now, the Rangers expect him to make his start, but will know more when he rejoins the team on Friday. Lee is expected to throw a side session in the bullpen on Saturday, and that will give the Rangers a better idea where he stands.

Lee went 1-4 with a 6.35 ERA in seven starts in August, and the back may have been a factor. Lee has had trouble getting the ball down in the strike zone, and having soreness in the lower back could have kept him from really driving downhill off the mound.

"That would be speculative on our part, but he did intimate he has been feeling it for longer than one start," Levine said.

"We'll see how it goes," manager Ron Washington said. "He didn't have a good August but if he drops three or four wins on us in September, we'll forget about August."