Padres SP Josh Johnson set for third Tommy John surgery

Padres pitcher Josh Johnson will be undergoing a third Tommy John surgery soon, sources have told CBS Sports MLB Insider Jon Heyman.

Johnson, who has experienced a setback in his latest comeback attempt while on a rehab assignment, could have the procedure scheduled as early as next week.

The right-hander signed a one-year deal with San Diego over the offseason, but has not been able to pitch for them. He has not appeared in a major league game since Aug. 6, 2013.