KANSAS CITY, Mo. (AP) Andy Reid was never under any pretense that Jamaal Charles was irreplaceable.

Shortly after the four-time Pro Bowl running back went down with a season-ending ACL injury, the Chiefs coach was among the first to acknowledge the difficulty in replacing him.

So far, that challenge has proven to be bigger than even Reid estimated.

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In their first game without No. 25 in the backfield, the Chiefs were bottled up a week ago by the Minnesota Vikings. Charcandrick West ran for 33 yards, Knile Davis managed just 13 more on five carries, and the Chiefs finished with 57 yards rushing in a 16-10 defeat.

In the five games before Charles was hurt? The Chiefs averaged 110 yards on the ground.

''There were some positive things that are going to get overlooked because we didn't win the game,'' Reid said. ''Charcandrick did some nice things - nice things, really.''

Then again, he also fumbled late in the game, squandering a chance at a go-ahead touchdown.

It's not just running back where the Chiefs are having trouble plugging holes, either.

Wide receiver Albert Wilson has been dealing with injuries most of the season, and fellow pass-catcher Jeremy Maclin could miss Sunday's game against Pittsburgh because of a concussion. So finding someone for quarterback Alex Smith to throw to has been another challenge.

Then there's the defensive side of the ball. Inside linebackers Josh Mauga and Ramik Wilson have been hurt much of the season, and outside linebackers Justin Houston and Tamba Hali showed up on this week's injury report. Nickel back Phillip Gaines recently had surgery on his torn knee ligament, robbing the defensive backfield of another playmaker.

But none of those losses has been nearly as visible - or nearly as devastating - as that of Charles, whose game-changing ability made him invaluable to the Kansas City offense.

The Chiefs (1-5) only managed 51 yards of first-half offense against Minnesota. If not for some points late in the game, they could easily have been shut out by the Vikings.

''Well, when Jamaal was there, we mixed our backs quite a bit as well, especially the last couple of weeks with Charcandrick,'' Chiefs offensive coordinator Doug Pederson said. ''I really don't think that those guys care who is back there. They're going to do their job whoever is carrying the ball, to break and bust that running back loose.''

The Chiefs have elected to give the bulk of the carries to West rather than Davis because his skillset happens to be closer to that of Charles - both are quick, shifty backs capable of making guys miss, while Davis is a bruising, downhill power runner.

''Right now,'' Reid said, ''we fit a little bit more into what Charcandrick does.

Never mind that West was an undrafted free agent out of tiny Abilene Christian, and Davis a third-round pick out of Arkansas who evidently doesn't fit the Kansas City offense very well.

Davis has also been productive when Charles has been hurt in the past.

He ran for 81 yards and two touchdowns in a playoff loss to Indianapolis as rookie, taking over when Charles went out with a concussion. Then last season, Davis rattled off back-to-back 100-yard performances against Miami and New England, both of which the Chiefs won.

But so far this season, Davis has been an afterthought. He's only had 16 carries all season, and twice he went through an entire game without touching the ball on offense.

''The things that we've been doing, we feel pretty good with what Charcandrick is doing and Knile working in on some other things,'' Reid said. ''We're not down on Knile by any means. That's not where we're at with it. Just with some of the things we're doing right now, Charcandrick kind of fits that.''

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