Dodgers pitcher Frankie Montas will miss the next 2 to 4 months after undergoing a procedure Friday to remove his right first rib.

Montas was acquired from the Chicago White Sox in December in the three-team trade that sent Scott Schebler and Jose Peraza to Cincinnati. The 22-year-old right-hander was expected to begin the season in the starting rotation at Triple-A Oklahoma City.

Pitchers and catchers report to spring training on Feb. 19 in Glendale, Arizona. A two-month timetable would allow Montas to return during the second week of the major league regular season.

A Dodgers spokesperson said that Montas first noticed discomfort in his ribcage during an off-season workout. The procedure was performed by Dr. Greg Pearl in Dallas, Texas — the same surgeon who performed thoracic outlet surgery on Dodgers pitcher Josh Beckett in 2013.

Montas made his major league debut with the White Sox in 2015 and appeared in seven games, starting two.