GARY Rowett wants his side to "make it happen" from the start against Birmingham City at The Den on Wednesday night.
Rowett felt his side were too reactive in the 1-0 defeat to Wigan on Saturday rather than taking the game to their opponents.
Millwall need to defeat 14th-placed Birmingham to ensure the gap to the top six isn't potentially up to 10 points with 11 games left when they face Bristol City on Saturday.
"When you start on the front foot with intensity, when you see people chasing with extra pace and intent, that's the key. When you see us move the ball with a bit more intent rather than slowly into midfield and back and around the back, that's not what we want.
"More often than not we've started well at home. The crowd will get behind us anyway, but we know if we start well the crowd will push us on and help that performance continue.
"But some games you start poorly and end up playing well, some games you start well and fade away. You can usually tell in the first 10, 15 minutes, are your team at it, do we look physically ready to put the opposition under pressure? Or is it a game where we're just going to wait and see what happens?
"Saturday was a bit like that, we looked like we were just waiting for something to happen rather than making it happen.
"[Making it happen] is something we look for in any team."
Rowett is set to be without midfielders Shaun Williams, Ryan Leonard and Ben Thompson for the clash against Pep Clotet's side.
Mason Bennett is in contention to start in attack after he impressed as a second-half substitute at the DW Stadium.
Millwall have failed to score in three of their last five fixtures. Rowett could switch back to a four-man defence and bring in an extra attacker against a Blues side that has conceded 52 league goals in 34 games this season.
But Birmingham are unbeaten in their last eight league games and their last five away from home.
Clotet is without Kerim Mrabti, Jacques Maghoma and Josh McEachran. He has named an unchanged side for the last two games, but has Maikel Kieftenbeld in contention.
Possible Millwall team: Bialkowski; Romeo, Hutchinson, Cooper, M Wallace; J Wallace, Woods, Molumby, O'Brien; Bradshaw, Smith.
Match odds: Millwall 11/10 Draw 11/5 Birmingham 5/2
Last meeting: Championship (November 30, 2019): Birmingham 1-1 Millwall (Clarke-Salter 79; Williams 61).
Image: Millwall FC