Worrell, who on July 21 had ulnar nerve transposition surgery, has been undergoing his rehabilitation at the Padres' Spring Training facility in Arizona. The Padres think that he can start throwing in Spring Training and return sometime this summer.
Worrell was acquired by the Padres with a player to be named -- who ended up as rookie Luke Gregerson -- from the Cardinals on Dec. 4, 2008, for Greene.
Worrell, 26, was non-tendered by the Padres following the season and removed from the 40-man roster. Worrell suffered the injury during Spring Training.
Gregerson, of course, became the key piece to the Greene trade. The right-hander became a key figure in manager Bud Black's bullpen, going 2-4 with a 3.24 ERA in 72 games. He had a 0.65 ERA in 37 games at PETCO Park.
Corey Brock is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.