Chargers running back Melvin Gordon is out Sunday night against the Steelers, but he could return as early as next week against the Bengals or the following Thursday night game against the Chiefs, sources told ESPN.

Whenever Gordon returns, "it won't be long now," one source told ESPN this weekend.

Until Gordon returns, Austin Ekeler will be the Chargers' primary running back, and rookie seventh-round pick Justin Jackson also figures to get some work.

But neither of those players is expected to get significant work for very long. The Chargers, according to a source, truly consider Gordon's knee a week-to-week injury. They want him to rest for now and, in the words of another source, "at least be ready for the K.C. game."

Gordon has rushed for 802 yards, sixth most in the league, and nine touchdowns this season. He suffered the injury in last Sunday's victory over the Cardinals.

The Chargers (8-3) enter Sunday one game behind the first-place Chiefs (9-2) in the AFC West. Kansas City will host the showdown between the divisional rivals on Dec. 13.