There was talk of Prior pitching his bullpen session on Sunday in San Diego, but as manager Bud Black explained, "Today is a scheduled off-day for the guys with extended Spring Training -- they have every Sunday off. So logistically, it was difficult to bring three or four guys and the coaching staff. So it's easier to deal with when everybody is there in Arizona."
Black said that the 27-year-old Prior would warm up in the 'pen and throw a batting practice session on Monday.
"I'm not sure of the number of pitches or the minutes," said Black, "but he will face hitters again. This will be his third session.
"We just want him to keep feeling good about his shoulder, and he is not having any setbacks about moving forward during rehab," he added. "The consistency is being able to get back on the mound. He's to a point where he was getting on the mound every fifth day. And then we started with throwing batting practice and taking a day off, back to the 'pen for a side session and two days off, and then another BP. He has been handling the sessions very well."
Prior was told by doctors that the tightness he experienced on Tuesday was not unusual, and Padres pitching coach Darren Balsley said that it wasn't a setback.
Prior will likely throw two more sessions and a simulated game, and is scheduled to appear in at least five Minor League games.
He's on the 60-day disabled list, so the Padres can't bring him back before June.
Sandy Burgin is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.