The two sides are separated by just a point in the Championship table, with the hosts three places behind after three consecutive league defeats.
Match preview
Millwall's Championship season got off to a relatively pleasing start under the management of Gary Rowett, as they put six points on the board in three games courtesy of wins over Stoke City and Coventry City either side of a defeat to Sheffield United.
Hoping to build on that, the Lions were able to snatch a point from nowhere in the following encounter away at Swansea City, as own goals from Ben Cabango and Nathan Wood levelled the game in injury time after the hosts had led 2-0, but they have not managed to add any points to their tally in three attempts since.
They firstly travelled to Carrow Road to take on Norwich City and were comfortably beaten as Joshua Sargent netted both goals in a 2-0 home win, before falling short at home to Reading with Naby Sarr's early goal proving decisive as they were again shut out by the opposition defence.
The Lions most recently travelled to Burnley on Tuesday and were kept out for a third straight encounter, with the contest remaining goalless until Vitinho opened the scoring on the hour mark and Jay Rodriguez wrapped up a 2-0 Clarets win 10 minutes later.
Now finding themselves in a concerning run of form having failed to find the net or pick up a point in the last three Championship outings, Millwall will be desperate to arrest their form on Saturday against another of the league's current strugglers.
Cardiff City had an identical start to that of their hosts in England's second tier, collecting six points from three outings as they firstly beat Norwich City before losing to Reading and winning 1-0 against Birmingham City thanks to Jaden Philogene-Bidace's early goal.
Steve Morison's side have also failed to put another win on the board in four matches since, as the second victory was followed by a commendable goalless draw away at West Bromwich Albion before being beaten 2-0 by Bristol City in a Severnside Derby at Ashton Gate.
Hoping to bounce back from that disappointment, the Bluebirds hosted Preston North End and played out a goaless draw, before welcoming Luton Town to South Wales in their most recent outing on Tuesday.
Luke Freeman put their visitors ahead in the opening minutes of the second half in that game, and Gabriel Osho doubled the visitors' lead on the stroke of half time, with Romaine Sawyers's 85th-minute goal not enough to spark a comeback as Morison's side fell to a 2-1 defeat.
Now sitting 17th in England's second tier, just one point better off than their hosts, Cardiff will look to make a return to winning ways at the Den and climb back towards the Championship's top half.
Millwall Championship form:
Cardiff City Championship form:
Cardiff City form (all competitions):
Team News
Millwall will likely remain without Ryan Leonard and Mason Bennett for Saturday's clash, with the former often playing an important role in either defence or midfield and the latter a notable absence up front.
In Leonard's absence, Shaun Hutchinson and Jake Cooper will again line up in a back three, with Charlie Cresswell and Murray Wallace likely fighting for the final spot, while Billy Mitchell will be vying for a return to the starting XI in midfield.
He could join George Saville in the engine room, while Benik Afobe may come back in to lead the line alongside summer signing Andreas Voglsammer and either Zian Flemming, Tom Bradshaw or Tyler Burey.
Cardiff are again without centre-back Curtis Nelson due to an injury, leaving Perry Ng and Cedric Kipre to partner up at the heart of the defence, while winger Callum O'Dowda is also set to be confined to the treatment room.
Joe Ralls, Ryan Wintle and Andy Rinomhota were preferred in midfield last time out, but Romaine Sawyers will be hoping to come in from the outset after his goal off the bench last time out.
There is also competition for places in the front three, with Jaden Philogene-Bidace and Rubin Colwill pushing to start after Sheyi Ojo and Mark Harris were deployed either side of Max Watters on Tuesday.
Millwall possible starting lineup:
Bialkowski; Hutchinson, Cooper, Wallace; McNamara, Saville, Mitchell, Malone; Voglsammer, Burey; Afobe
Cardiff City possible starting lineup:
Allsop; Romeo, Ng, Kipre, Nkounkou; Sawyers, Ralls, Wintle; Ojo, Watters, Philogene-Bidace