Pittsburgh Pirates right-hander Charlie Morton may require season-ending Tommy John surgery, according to Michael Sanserino and Bill Brink of the Pittsburgh Post-Gazette. Morton has been out since the end of May with inflammation in his right elbow.

Morton reportedly tweaked his injury Sunday while throwing a bullpen session. The 28-year-old had his elbow examined by a doctor this week and the Pirates are awaiting word on whether or not he will require surgery.

Prior to his injury, Morton had started nine games for the Pirates this season. Over his 50 1/3 innings pitched, Morton maintained an ERA and WHIP of 4.65 and 1.45 with 4.5 SO/9 and 2.0 BB/9.

Morton was acquired by the Pirates in 2009 in the trade that sent Nate McLouth to the Atlanta Braves. After a pair of less-than-spectacular seasons in Pittsburgh, Morton posted solid numbers in 2011. Over his 29 starts spanning 171 2/3 innings, Morton maintained an ERA and WHIP of 3.83 and 1.532.