Injury-plagued Miami took another hit with the announcement that Opening Day starter Edinson Volquez will undergo Tommy John surgery Friday.

Volquez had been sidelined since July 17 because of a left knee injury. The Marlins' opening starter went 4-8 with a 4.19 ERA in 17 starts and threw the only no-hitter in the majors this year. He's under contract for $13 million next season.

Shortstop JT Riddle will also miss the rest of the season because of injuries, manager Don Mattingly said Tuesday. Riddle has been out since July 19 with a left shoulder injury that will require surgery next week. He batted .250 in 70 games as a rookie this year.

In addition, first baseman Justin Bour is expected to be sidelined another four to six weeks because of a strained right oblique, and it'll be at least three weeks before he resumes any baseball activities, Mattingly said. Bour has 21 home runs and 63 RBIs.

The outlook is better for a couple of other players on the disabled list. Right-handed reliever Kyle Barraclough, sidelined with a right shoulder impingement, is expected to throw a bullpen session this week. He and third baseman Martin Prado, recovering from right knee surgery, are expected back before the end of the season, Mattingly said.

The Marlins appear headed for their eighth consecutive losing season.

Information from The Associated Press was used in this report.