(Reuters) - Washington Redskins running back Matt Jones suffered a sprained left shoulder in a preseason game against the New York Jets on Friday, putting his availability in doubt for the start of the regular season.

Jets defensive back Calvin Pryor pushed Jones out of bounds before landing on him to force the rusher out of the game in the opening quarter.

Redskins coach Jay Gruden said Jones has a slight separation but does not think he has a long term injury.

"When I went down, on a (pain) scale from 1 to 10 it was about a seven," Jones told reporters. "As it settled down (the pain went down). I still have some flexibility in it now so it's not as bad as it was."

Jones is slated to be the top runner in Washington this season.

The second-year player rushed for 490 yards last year while splitting time with running back Alfred Morris who has since left to sign with the Dallas Cowboys.

(Writing by Jahmal Corner in Los Angeles; editing by Sudipto Ganguly)