"I've been waiting for that for a while," Pryor said. "It's been a long, patient offseason. I felt good today. I didn't have any setbacks, so that's always a positive."
Pryor attempted to return in midseason last year, but had trouble with his triceps muscles and an MRI test showed the repaired lat tendon had retracted and reattached to his tricep. The subsequent surgery to reattach that tendon is rare, with Jake Peavy the only Major League pitcher ever to have undergone the procedure.
Manager Lloyd McClendon said Pryor is ahead of schedule on his return, but the club will be cautious.
"He threw extremely well and had a big smile on his face," McClendon said. "We're very pleased. We'll just keep him moving forward. You get a guy like that healthy and back to where he was, he has the ability to help shorten up games."
The hard-throwing 24-year-old was projected to be a big part of the Mariners bullpen last year and didn't allow a run in his first seven appearances before his injury problems cropped up.
"What I told him is just keep progressing," said McClendon. "Don't get in a hurry. I know he's anxious because he's feeling good, but he has to continue to do what the trainers and doctors want him to do and keep moving forward."
"I'm antsier than I should be," Pryor acknowledged. "But our training staff has been good as far as just updating me and rolling with it day to day. Not making set plans, but just adjusting to how I'm feeling and progressing.
"Hopefully, I'll throw a few more bullpens, start doing some live BP and then be in the mix with everybody else," he said. "At this point, I don't think there is a schedule. If I threw five bullpens and feel really good, maybe I'll go into a game. Maybe it takes seven. I don't know at this point. It'll just be an adjustment, day to day thing."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.