The Denver Broncos' stunning victory last week that kept them unbeaten hasn't done anything to allay coach Gary Kubiak's concerns over their nonexistent running game.

Sunday night's matchup with the Detroit Lions, winless in part because of their inability to stop the run, might be what Denver needs to start establishing a badly needed ground attack.

The Broncos stunned Kansas City 31-24 last week, as Manning directed a touchdown drive to tie it in the final minute and cornerback Bradley Roby returned Jamaal Charles' fumble 21 yards for another score with 27 seconds left.

''I've been involved in a couple of pretty crazy games,'' said Manning, who threw for threw for 256 yards and three touchdowns along with an interception returned for a score, ''but nothing quite like this.''

There have been whispers that Manning's days as an elite quarterback are coming to an end since late last season, but it's hard to judge that accurately this year given the fact he's been sacked seven times and hasn't had the help of an effective ground game.

Denver (2-0) is 29th in the league with 65.0 rushing yards per contest. Ten of Pro Bowl running back C.J. Anderson's 24 carries have gone for no gain or negative yards, while Ronnie Hillman has been stuffed at or behind the line of scrimmage on seven of his 21 carries.

''The biggest thing right now offensively to me is protecting the quarterback and finding a way to make big plays,'' Kubiak said. ''And the thing that enables you do to those two things is running the football.''

The Broncos were outrushed 144-61 by the Chiefs. Manning has called nearly 60 percent of Denver's plays from the shotgun, which could also contribute to the running game's struggles.

Kubiak, known for his rush-heavy approach as Houston's coach for the previous eight seasons, agrees - to a point.

''Running out of the gun is a challenge at times,'' he said, ''but if that's something you're doing best, you've got to find a way to run it that way. But being physical is a state of mind. It's an identity. It's a commitment.''

Denver's new-look offensive line jelling might change the ground game's fortunes substantially. Free-agent signee Evan Mathis, the left guard, didn't play in the preseason and is among four new starters on the line absorbing Kubiak's new scheme.

The process could be accelerated against the Lions (0-2), who rank 28th with 147.0 rushing yards allowed per game and were gashed for 199 in 26-16 loss to Minnesota last week - 134 by Adrian Peterson.

The offseason departure of defensive lineman Ndamukong Suh appears to have gutted Detroit's run defense. It topped the NFL with 69.3 yards given up per game last year.

The Lions also aren't doing any better than the Broncos in protecting their quarterback. Matthew Stafford was sacked once and hit often by the Vikings, leading to him needing X-rays on his chest and ribs afterward.

As with Manning, a lack of a ground attack has led to Detroit's QB being pounded. The Lions are averaging 53.5 yards rushing - second-to-last in the league.

''Anytime you have a game like this where you fall behind to a really good team and we weren't successful running the football, you're going to have to drop back and throw it, which we had to do,'' said Stafford, who went 32 of 53 last week. ''And that doesn't put anybody in a good position, but it's what you have to do to try to win the game.''

Denver's pass defense easily tops the NFL at 135.0 yards allowed per contest.

Making their season debut at Ford Field could help the Lions avoid their third start of at least 0-3 in five years. Detroit has won four in a row and 10 of 13 at home.

The Lions, though, have lost their last two matchups with the Broncos by a combined 89-17, and this meeting with Manning is followed by a trip to Seattle the following week.

''We get paid to perform well, we get paid to win football games and certainly we haven't done that as of yet,'' coach Jim Caldwell said. ''But do I believe that we have a group that can get it done? You better believe it.''