Updated

MIAMI (AP) -- The Miami Marlins probably should not count on players returning from the disabled list to spark a late-season turnaround.

Right-hander Edinson Volquez and shortstop J.T. Riddle will miss the rest of the season because of injuries that may require surgery, manager Don Mattingly said Tuesday. Volquez has been sidelined since July 17 because of a left knee injury, and Riddle has been out since July 19 with a left shoulder injury.

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 activity, Mattingly said. Bour has 21 homers and 63 RBIs.

Volquez, the Marlins' opening day 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.

Riddle batted .250 in 70 games as a rookie this year.

The outlook is better for a couple of other players on the disabled list. Right-handed reliever Kyle Barraclough, sidelined with 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.