"It's getting better each time but when those small muscles in your back lock up, they won't let you push through it," McClellan said. "You have to take your time to get back. It has to do with the surgery but the good news is the repair site is not the problem. A week ago I felt great. But I haven't faced hitters since May and this is part of the process."
The danger is falling behind in the fifth-starter competition but there is no immediate danger of that. The Rangers played just the first of a record 38 exhibition games on Friday.
"This is a long spring and I'm not the type of guy who takes a whole lot of time to get ready," McClellan said.
But McClellan can also take his free agency on March 22 if he is not added to the 40-man roster. He is one of five players with "out" dates in their contracts. The others are pitcher Yoshinori Tateyama (March 24), Brandon Snyder (March 29), Jeff Baker (March 31) and Jacob Brigham (March 31).