Karstens (shoulder) announced his retirement from professional baseball Sunday on his personal Twitter account.

The 32-year-old was forced to shut down his career after requiring surgery on the labrum and rotator cuff of his right shoulder in 2013. Karstens spent seven seasons in the big leagues with the Yankees and Pirates, accruing a 26-40 record, 4.44 ERA, and 1.33 WHIP over 592 career innings.

Jeff Karstens (shoulder) is planning to work out for interested major league teams in January.

Karstens is on his way back from shoulder surgery but should head into spring training with a clean bill of health. The 31-year-old right-hander has a 4.44 career ERA and 1.33 career WHIP in 592 1/3 MLB frames.

Jeff Karstens (shoulder) was re-evaluated in Pittsburgh on Saturday.

He returns to Pirate City in Bradenton, Fla. on Sunday to continue a throwing program. Karstens underwent rotator cuff and labrum surgery on Friday. He should be ready to go again in spring training.

Jeff Karstens (shoulder) underwent surgery on Friday.

The Pirates have yet to provide any additional details. Karstens was placed on the 60-day DL last month and remains out indefinitely.

Pirates transferred RHP Jeff Karstens from the 15-day disabled list to the 60-day disabled list.

Karstens had been aiming to join the Pirates' starting rotation in early June but began experiencing more shoulder problems last week. The righty is out indefinitely.

Jeff Karstens (shoulder) will be re-evaluated next week after having his throwing program shut down on Friday due to pain in his right shoulder.

Karstens had been expected to return to the Pirates' rotation in early June, but now that timetable will certainly be pushed back. He has dealt with discomfort in his shoulder since early in the spring.

Jeff Karstens has been shut down after feeling pain in his right shoulder during his throwing program on Friday.

Karstens was initially expected to return to the Pirates by early June, but it looks like that timetable will need to be pushed back now. It's also unclear whether he'll work as a starter or reliever once he does make his way back.

Jeff Karstens (shoulder) will make his next rehab start Saturday with Double-A Altoona.

Karstens, currently working his way back from shoulder inflammation, gave up one run in three innings Monday in his first rehab outing with High-A Bradenton. He could join the Pirates by the end of the month, though it isn't clear what his role will be.

Jeff Karstens (shoulder) is slated to throw 50 pitches over three innings in a rehab start with High-A Bradenton on Monday.

He was cleared to begin a rehab assignment after tossing 29 pitches in a two-inning start in extended spring training on May 8. Karstens had a setback with his shoulder towards the end of spring training but appears to be back on track. He could be ready before the end of the month.

Jeff Karstens (shoulder) is scheduled to pitch in extended spring training on Monday.

Good news for Karstens, who made it through a two-inning simulated game with no issues. If all goes well in extended spring training, he will begin a minor league rehab assignment with High-A Bradenton on April 13. He's likely a few weeks away from joining the Pirates and there's a chance he could do some in long relief.

Jeff Karstens (shoulder) is scheduled to throw a simulated game Friday.

Assuming all goes well, a rehab assignment could the next step. Karstens has been sidelined since the middle of spring training due to right shoulder inflammation. He's expected to be stretched out as a starter, but the Pirates could bring him back as a long reliever.

Jeff Karstens (shoulder) threw a simulated game Thursday.

Karstens had a setback toward the end of spring training, but could soon be ready for a rehab assignment with High-A Bradenton. The Pirates will stretch him out as a starter for now, but he could be brought back as a long reliever.

Jeff Karstens (shoulder) will throw a simulated game on Thursday.

Karstens had a setback earlier this month but has resumed throwing. A timetable for his return has not been established, but he appears to be back on the right path.

Jeff Karstens (shoulder) threw a 30-pitch bullpen session Thursday.

Karstens had Dr. Neal ElAttrache observe his shoulder in Los Angeles and received a more specific diagnosis on his shoulder. He wouldn't go into detail on what he was told, but he said it was "relieving." It's not clear when he'll be ready to go out on a rehab assignment, but he's on the right track.

There is no timetable for when Jeff Karstens (shoulder) will resume throwing off a mound.

Karstens has resumed playing catch, but he's yet to be cleared to step atop the bump again. Recovering from inflammation in his pitching shoulder, it will obviously be a while before he's ready to rejoin the Pirates' rotation.

Jeff Karstens (shoulder) could begin throwing off flat ground by the end of this week.

Karstens was placed on the 15-day disabled list on March 31 with right shoulder inflammation. There is no timetable for his return to the Pittsburgh rotation.

Pirates placed RHP Jeff Karstens on the 15-day disabled list, retroactive to March 22, with a right shoulder injury.

Karstens is dealing with lingering shoulder discomfort and it's still not clear at this point how long he'll be sidelined. Jeff Locke and Jonathan Sanchez will open the season in the Pirates' starting rotation.

Jeff Karstens was scratched from Sunday's start due to lingering shoulder discomfort and is expected to begin the season on the disabled list.

Jeff Karstens (shoulder) is scheduled to throw a side session Saturday.

Assuming all goes well, Karstens will then pitch two innings on Monday, either in a Grapefruit League game or a minor league game. He's going to be cutting it close to be ready for the start of the season.

Pirates manger Clint Hurdle said Wednesday that Jeff Karstens (shoulder) remains on track to take his first turn in the rotation when the season begins.

Karstens has yet to make his Grapefruit League debut due to a shoulder/biceps issue, but he appeared in a minor league game Wednesday. He won't be able to afford any setbacks or a DL stint will be required.