Sources: Seahawks RB Turbin underwent offseason hip surgery

Seattle Seahawks running back Robert Turbin underwent offseason hip surgery, sources told FOXSports.com. The timetable for Turbin's return to the field is unknown.

Turbin, who is entering the final year of his rookie deal, appeared in all 16 regular-season games and each postseason contest for Seattle last season.

Turbin is penciled in to share carries with Christine Michael behind Marshawn Lynch in the upcoming season.

The 5-foot-10, 222-pound running back has rushed for 928 yards on 231 attempts in his first three seasons with the Seahawks. 

The Seahawks signed Lynch to a two-year extension through the 2017 season in March.