Kansas City, Mo. ? Donald Stephenson and Geoff Schwartz might as well consider themselves starters the way the two Chiefs offensive linemen have been pressed into service this season.

In an ideal world, Stephenson is supposed to be the backup offensive tackle, Schwartz the reserve offensive guard. But a series of injuries to just about everybody on the Chiefs’ already suspect line has resulted in each of them playing in every game this season.

Not just on special teams, either.

In fact, Stephenson had to make a spot start at right tackle when No. 1 overall pick Eric Fisher was dealing with the after-effects of a concussion. Schwartz did the same at right guard in the opener when Jeff Allen was ailing and at left guard when Jon Asamoah was out.

Stephenson has played in seven games on offense, Schwartz in five of them.

Now, with Fisher again dealing with a shoulder injury and Asamoah hobbled by calf spasms and a shoulder injury, Stephenson and Schwartz might just make up a retooled right side of the Kansas City offensive line when the San Diego Chargers pay a visit on Sunday.

“Luckily those guys have gotten a lot of reps this year,” Chiefs quarterback Alex Smith said. “They’ve both played, and when they’ve come in, they’ve played well. I think everyone is expecting for them to come in and we won’t skip a beat.”

It’s not as if the offensive line has been the strength of the Chiefs. The Chiefs have given up 29 sacks this season, putting them in the bottom third of the NFL, and have been a big reason why Kansas City has struggled to score touchdowns rather than field goals in the red zone.

Last Sunday at Denver, the Chiefs had first-and-goal at the 2-yard line. Jamaal Charles was stuffed, fullback Anthony Sherman managed a yard, and Charles was stuffed again, forcing Kansas City to kick a field goal that closed the gap to 17-10 at halftime. The Broncos went on to win 27-17 and take control of the AFC West.

“I mean, you know what? I think the next guys have to step up,” Smith said, “and we have great depth up front. We have some guys ready to go, and that’s the way it should be. We hope to get those guys back that were banged up, but that’s the nature of football. You have to be able to battle through injuries, and you have to be able to step up and fill the void.”