First, though, Rodriguez will get a second opinion before committing to the operation, which typically calls for a year's worth of recovery time.
The 28-year-old pitcher initially experienced elbow soreness in Monday's game against the Padres. He made just seven pitches before departing with a trainer, which led to a visit with associate team orthopedist Dr. Will Workman.
Workman discovered the UCL damage via MRI results and recommended Tommy John surgery, normally the standard route to take with such an injury. But manager Bob Melvin said Rodriguez and his agent planned to seek another doctor to "talk about what the next course of action might be."
Rodriguez's chances of making the team out of camp were slim, considering the bullpen is already crowded with proven arms. The righty made 71 appearances for the Astros in 2012, pitching to the tune of a 5.37 ERA with 78 strikeouts in 70 1/3 innings.
Jane Lee is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.