Read our in-depth guide to tonight's game at The DenMillwall head into Tuesday night's visit of Barnsley looking to make amends following the disappointing defeat to Coventry City last Saturday.
The Tykes visit SE16 having won one of their two League games so far, a 1-0 success at home to Burton, though they lost 3-1 to Chesterfield last time out.
What the managers say
Neil Harris: "It's a great opportunity for us to put things right that were wrong (on Saturday).
"I'm delighted that the game has come as quick as it has and it's at The Den. We will be better, that's for sure.
"Barnsley are a good team and it's another stern test for us. They will be well organised and they will definitely be physical, but they've got some good footballers as well."
Watch the manager's full pre-match interview on Lions PlayerHD.
Lee Johnson: "I've played there (The Den) before and it takes a certain type of character to be able to go and produce on a stage like that.
"It's a really, really tough environment to play at The Den and our players should embrace it. They should go there with no fear, nothing to lose and that mentality to go get a result."
Read more from Barnsley's head coach by clicking here.
Harris hinted after Saturday's defeat to Coventry that he could make changes to the starting Xl for the visit of Barnsley.
Jimmy Abdou and Aiden O'Brien have both returned to training following hamstring and ankle injuries respectively, and the former could certainly come into contention for a return should he be able to prove his fitness.
Young midfielder Ben Thompson impressed on his League debut after coming off the bench against Coventry and is also vying for a starting berth in midfield.
Shane Ferguson, who also entered the action for the second-half against The Sky Blues, is pushing for a start.
Joe Martin (ankle) remains sidelined.
Tykes boss Johnson has a selection dilemma in midfield with Conor Hourihane, Joe Rothwell and Daniel Crowley all in contention to start.
Australian winger Ryan Williams could also make his first appearance of the season.
Millwall and Barnsley have met on 52 previous occasions and to date there is nothing to separate the two sides with 20 wins each and the remaining 12 ending in draws.
The most recent meeting was in February 2014, when The Tykes were 1-0 winners at Oakwell, though The Lions did win the earlier reverse fixture that season by the same scoreline.
Unable to make it to the game? You can still follow all the action as it happens by tuning in to live match commentary on Lions PlayerHD.
Live updates will also be being posted via @MillwallFC, the club's official Twitter account.
For a comprehensive list of odds on the game visit Sky Bet.