FORT MYERS, Fla. -- While the rest of the players were taking batting practice on a back field because of a problematic sprinkler system, Brad Penny was throwing a bullpen session on one of the back mounds. After being pushed back from his scheduled start last Thursday because of some shoulder weakness, Penny's progress was delayed until this morning's bullpen session.

"The intensity was greater today than at any time in spring training, so all positive signs," pitching coach John Farrell said. "The benefit of the aggressive throwing on flat ground was to get his lower half more engaged in his delivery, to transfer the energy from his legs through his upper body out to his arm, rather than trying to generate all the velocity with his arm. He's been able to do that, and there's been no discomfort or restriction in his delivery or his arm action.

"When you're trying to manufacture all that with the arm, you're stressing it probably more so than you are with a full delivery, a normal delivery at game intensity. So part of it is getting his lower half more active. That's translated [into] better arm speed."

Penny has been throwing off flat ground since he first experienced the discomfort in his arm. Farrell said the plan is to have him throw batting practice on Tuesday, and perhaps follow that with an "intersquad-type situation." Penny does not yet have a date to throw in a game in spring training.

"Certainly after being pulled out of the BP session, and then having to get back to flat ground work and then the mound progression, it takes us away from that original calendar. But to say it's seven, 10 days, two weeks, I think that's probably too early to tell. But the most encouraging thing is that there was no discomfort of any kind today, and there hasn't been over the last four sessions on flat ground."