With competitive football not taking place for either team at the moment, putting on a game like this will serve to keep each squad fresh ahead of the return.
Match preview
Millwall head into this match on the back of three undefeated games in the Championship, which is a record the team will want to continue through this friendly period.
Gary Rowett has guided his team into the playoff positions during the first half of the season, and his team is one filled with confidence.
Offensively Millwall have been strong so far, scoring 26 goals across the opening 20 matches in the Championship, and that was exemplified by their most recent performance.
The Lions defeated Preston North End 4-2 before the World Cup with Zian Flemming getting himself a hat-trick in that match.
With this being Millwall's only scheduled friendly at the moment, Rowett will likely use this as a focused game to gain fitness and keep his team sharp, but a good performance would also go along way.
The 11-time Danish champions will also be out to pick up as much momentum as possible in this match, as they only have one other friendly match announced so far.
That one will take place against Tenerife in December, the fixture against Millwall should be a tough and genuine test for the squad.
Brondby currently find themselves 10th in the league at the moment, which does leave them in the relegation round.
Because of that Niels Frederiksen will want to see more from his team in this particular match so they can begin preparing for the return of league football in a more impressive manner.
Brondby are without a win in their previous two matches heading into this one, which will put plenty of pressure on the team to get back to winning ways.
Millwall Club Friendlies 1 form:
L
W
W
D
Millwall form (all competitions):
W
W
L
D
D
W
Brondby form (all competitions):
W
D
D
W
D
L
Team News
Millwall will be boosted by the fact that they have an entire squad to pick from that has not been altered by the World Cup, meaning Rowett can make this match work in his favour.
Of course, with this just being a friendly it is likely the Lions will look to rotate the team a lot to give other people the chance to perform, particularly for those needing minutes.
Benik Afobe will be missing for Millwall though as he has been ruled out until after the World Cup due to a knee issue.
For the visitors, it will be Ohi Omoijuanfo who gets the chance to start up front as he continues to work as a lone striker for the Danish team.
Elsewhere, there will likely be more changes made to the team throughout the game to provide as many minutes to the squad as possible.
Millwall possible starting lineup:
Long; McNamara, Cresswell, Cooper, Malone; Mitchell, Saville, Honeyman, Flemming, Burey; Bradshaw
Brondby possible starting lineup:
Hermansen; Riveros, Tshiembe, Maxso, Gammelby; Wass, Radosevic; Hedlund, Greve, Vallys; Omoijuanfo
We say: Millwall 2-0 Brondby
Brondby are sure to provide a stern test for the home side at the weekend, as they are aiming to get their own season back on track with these friendlies.
However, Millwall should have enough to get the victory, particularly with the form they have displayed so far.