"Chad Pennington hasn't decided if he's calling it a career.

The Miami Dolphins quarterback said he's about "50-50" on whether to continue playing or move onto the next phase of his life.

His right shoulder will be operated on Friday for the fourth time in seven years by Dr. James Andrews. That's the biggest reason Pennington might be leaning toward retiring after 11 productive seasons with the Jets and Dolphins — unless his competitive juices convince him to keep going.

"There is no doubt I can come back, but I would have to weigh whether I'd be a liability or an asset,'' Pennington said. "That's important to me. I can only step out on the field if I feel like I can help. To rehab and come back and throw the football again at a high level, I can do that. Whatever it takes. But to be able to step on the field and not be a liability, doubt whether this thing is going to pop out again, that's going to be the issue, the question."

Because of the previous shoulder procedures Pennington has been told MRI's of the injury are difficult to read. That why doctors have no idea how much damage was done when Pennington's right arm jammed into the back of left tackle Jake Long when he was hit by Titans defensive end Jason Babin in his lone start of the 2010 season.

Pennington said Andrews will be able to provide more clarity on the rehab process once he's seen the damage and has fixed it. If it's a torn anterior capsule, which Andrews suspects, and there's no muscle damage, then it won't be impossible to come back yet again."