Kansas City, Mo. ? The Kansas City Chiefs’ defensive struggles late in the regular season have raised doubts about their prospects for postseason success.

The Chiefs (12-3) already are AFC West champions, thanks in large part to their hot 9-0 start. But they have allowed 45 points in each of their last two road games — both lopsided losses that could cost them homefield advantage through the postseason.

And they don’t want to go on the road, after losing three of their last four games away from Arrowhead Stadium.

In those three losses, including Saturday’s 45-20 blowout at Minnesota, opponents have averaged 38 points, 231 yards rushing and 474.6 total yards.

“The one thing we did not want to sacrifice was the momentum,” said Pro Bowl running back Priest Holmes, who tied Emmitt Smith’s NFL record of 25 touchdowns rushing. “We definitely have some things to work on.”

Opponents are averaging 21.9 points against the Chiefs, who for a second straight year face the prospect of having their spectacular offensive achievements done in by the defense.

Only one team has reached the Super Bowl after allowing more than 21 points per game in the regular season. The 1983 Raiders won the title after yielding an average of 21.1 points through their first 16 games.

The Chiefs finish the regular season Sunday at home against Chicago, and a victory would make them 13-3. The Colts’ loss Sunday to Denver ensured K.C. a first-round bye.

“We know we have one game to go, and we know what’s at stake,” said Holmes. “We’ve definitely made the playoffs and we’ll definitely be a better team. You can’t play a half, two quarters, in the NFL and expect to win.”