"It's a variable in our schedule," Maddux said. "Spring training works backwards from Opening Day. If you stay on schedule, you kind of build up for Opening Day. But it may, it may. He might be late. We've also had guys who started off a week late and threw them in the fifth starter spot with a day off and they don't miss a beat."
Webb was scheduled to throw a bullpen session Sunday, but the team decided to be cautious with him after he had a "heavy long toss" session Saturday.
Maddux said until Webb has his full arm strength, he won't get back on a mound. Webb, who did throw lightly Thursday so Maddux could take a look at him, has pitched just four innings the past two seasons and had shoulder surgery in August 2009.
"I feel good, I really do," said Webb, who threw Sunday for about 15 minutes from 110 feet. "I come in and he [Maddux] lets me know what I'm doing."
Webb, who said he hasn't had any setbacks in camp, admitted that he tried to rush back last season, and the club wants to be sure that he's healthy -- even if that impacts whether he can start the season on time.
"We want guys coming back only once," Maddux said.
Richard Durrrett covers the Rangers for ESPNDallas.com.