All you need to know ahead of Tuesday night's clash...
Millwall will look to make it 14 games unbeaten in all competitions when they host Chesterfield in Sky Bet League One on Tuesday night (kick-off 7.45pm).
After claiming a third Premier League scalp of 2017 in The Emirates FA Cup on Saturday in a 1-0 defeat of reigning champions Leicester City, Neil Harris' side return to League One action as they chase a top six spot in the table.
It will be the 39th meeting between the two sides, with Millwall in the ascendancy, having won 17 matches to The Spireites' 14.
Steve Morison was at the double the last time the two teams locked horns, with Shane Ferguson's goal adding the gloss to a 3-1 victory in August 2016.
Strikes from Aiden O'Brien and Lee Gregory nudged The Lions into the Play-Off spots in January of that year in a 2-1 win, as Millwall gained revenge following a 2-0 defeat at The Den earlier in the campaign.
Poul Hubertz stepped off the bench to head a late winner in February 2007, after a tight encounter was locked at 1-1 following Darren Byfield's opener and Paul Hall's equaliser.
More historically, Dean Horrix, Nicky Chatterton and Alan West were on target as The Lions defeated The Spireites 3-2 in May 1982, whilst Jimmy Whitehouse, Len Julians (2) and Dennis John helped Millwall on their way to a 4-2 win in November 1964.
Millwall's biggest win over Chesterfield came in the two clubs very first meeting in 1931, as The Lions won 5-0.
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