According to CBS Sports' Jon Heyman, free agent Roy Halladay has decided to retire from baseball.

Halladay, who had spent the past four seasons pitching for the Phillies, signed a one-day contract today with the team that drafted him -- the Blue Jays -- so that he could officially call it quits in that uniform.

"He was one of the best competitors who ever played this game and taught everyone around him to prepare the right way in order to be the best," said Phillies pitcher Cole Hamels.  "For me, personally, he helped me understand the game more and gave me insight on how to become a top of the line starting pitcher."

Halladay, 36, underwent shoulder surgery in mid-May with a 2-4 record and 8.65 ERA to remove a bone spur in his shoulder and repair his torn rotator cuff. He came back but continued to deal with shoulder issues throughout the 2013 season put up an ugly 6.82 ERA across 13 starts in 2013.

Halladay missed significant time during the 2012 season due to shoulder issues, going 11-8 with a 4.49 ERA, showing signs of finally slowing down after a decade of dominance.

"Roy Halladay is the ultimate competitor," Phillies second baseman Chase Utley said.  "He is by far the hardest worker that I've ever seen and treated every game as if it were his last.  It was no coincidence why he was the best pitcher of his era.  I'm honored to have had the opportunity to watch him pitch for four years.  I'll miss his presence and passion but, most of all, I will miss his intensity.”

The right-hander will finish up with a 203-105 career win-loss record and a 3.38 career ERA.