While the home side occupy 12th place in the standings, the visitors are down in 15th spot, albeit having put together a three-match undefeated run.
Match preview
Given how they missed out on the playoffs in 2022-23, Gary Rowett has had a tough job on his hands to lift his squad, many of whom have remained at the club.
Three successive defeats to Bristol City, Reading and Norwich City in all competitions - conceding eight goals in the process - suggested that it may be a long season for the Lions.
Since then, though, four points have been accumulated from fixtures against Stoke City and Birmingham City, the 1-0 win over the former being their second success by that scoreline this season.
Although Millwall continue to possess one of the worst attacking records in the division, they have one of the best defences, with three of the five goals that have been shipped coming in the 3-1 reverse at Norwich.
With Allan Campbell and Ryan Longman having arrived from Luton Town and Hull City respectively just before the closure of the summer transfer window, Rowett will hope that they can aid Millwall's efforts going forward.
Leeds also had a busy end to trading, seeing Cody Drameh, Sam Greenwood and Luis Sinisterra replaced by Ilia Gruev, Glen Kamara and Jaidon Anthony.
As it stands, it remains to be seen who has gotten the better deal, but head coach Daniel Farke will be delighted that he can finally work with a settled squad.
Accumulating just six points from five games would not have been what Farke envisaged, their only success being a dramatic 4-3 comeback win at Ipswich Town.
That was followed by a first clean sheet of the season being kept at home to Sheffield Wednesday, albeit in a goalless draw that was viewed by a huge disappointment by their supporters before the international break.
Millwall Championship form:
Millwall form (all competitions):
W
L
L
L
W
D
Leeds United Championship form:
D
L
D
W
D
Leeds United form (all competitions):
W
L
D
W
L
D
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Team News
With Shaun Hutchinson having suffered a calf injury against Birmingham, Wes Harding is in line to start in the Millwall defence.
Although Rowett will be satisfied with the greater depth to his squad, he may feel inclined to stick with the rest of the starting lineup from the last game.
Campbell and Longman will both be considered for full debuts, though, particularly the latter who may be used on one of the flanks.
Despite the frustration of the Sheffield Wednesday contest, Farke will also keep changes to a minimum for the encounter in East London.
Djed Spence is an option at right-back, yet is unlikely to replace Luke Ayling, but Kamara may get the nod over teenager Archie Gray.
Millwall possible starting lineup:
Sarkic; Leonard, Harding, Cooper; Norton-Cuffy, Mitchell, Saville, Wallace; Bradshaw, Flemming, Nisbet
Leeds United possible starting lineup:
Meslier; Ayling, Rodon, Struijk, Shackleton; Kamara, Ampadu; Summerville, Piroe, Gnonto; Rutter
We say: Millwall 1-2 Leeds United
With both teams having improved in recent matches, this should prove to be a competitive contest, one that the home side will fancy their chances of winning. However, despite Leeds remaining in a transitional period under Farke, we expect their greater firepower to come through at The Den.