"I guess you'd say it kind of surprises you, but I guess it doesn't with him," Pettitte said. "He's just the ultimate competitor. I know he loves to compete, and I wish him nothing but the best."
Clemens, 50, has signed with the independent Sugar Lake Skeeters and will start on Saturday. In a news conference on Tuesday, Clemens -- who hasn't pitched in the big leagues since 2007 with the Yankees -- said that he doesn't consider himself Major League-ready.
Still, Pettitte isn't quite sure that the Rocket wouldn't try to relaunch his big league career if Saturday's effort goes well for the seven-time Cy Young Award winner.
"I don't know," Pettitte said. "I guess you'd think, 'Why do it unless you're trying to?' I'm not real sure, to tell you the truth. But if he's trying to, if anybody could do it, he's definitely somebody that could pull it off, probably."
Pettitte and Clemens, of course, were once close friends and workout partners during their Yankees years together. Their relationship has been viewed in a different light since Clemens' federal perjury trial, which ended with an acquittal in June.