INDIANAPOLIS (AP) -Peyton Manning is in charge of an undefeated team, leads the AFC in passer rating and is on a record pace for yards passing.

And it still isn't good enough.

The three-time MVP acknowledged Wednesday there's still room for improvement in the Colts offense. He expects more third-down conversions and more touchdowns in the red zone after settling for four field goals in last weekend's 18-14 victory over San Francisco.

The Colts (7-0) host Houston (5-3) in an AFC South clash this weekend.