"Don't even mention to Broncos running back Knowshon Moreno that perhaps he has hit the "rookie wall."

The team's first-round draft pick doesn't believe it exists.

"I just don't," Moreno said. "I haven't hit one yet, so I'm not worried about it."

But it's a valid question after Moreno's rushing production has dropped in the past two weeks.

After rushing for more than 80 yards in games nine through 12, including a season-high 97 against Washington on Nov. 15, Moreno had only 63 yards against Indianapolis and 42 last week against Oakland, both times as the primary tailback with veteran Correll Buckhalter sidelined with an ankle injury.

His second-half production has declined in those games too, especially against Oakland, when Moreno rushed nine times for a total of minus-1 yard after halftime.

Coach Josh McDaniels said any decline by Moreno is a result of an all-around failure by the running game, and not a sign that his rookie rusher is wearing down."