All you need to know about Saturday's game
Millwall head to the Weston Homes Community Stadium to face a rejuvenated Colchester United side on Saturday with both teams desperate to secure three points.
The Lions moved back up to fifth in the League One table, three points clear of seventh placed Barnsley, with Monday night's excellent 2-0 victory over table-topping Burton Albion.
However, with seven games to go and 21 points still to play for, there could be plenty more twists and turns at both the top and bottom of the table before the season's conclusion on Sunday 8th May.
Relegation-threatened Colchester United are as determined to gain maximum points on Saturday, but for very different reasons as they battle to stay in League One for another year instead of leaving it, as The Lions want to.
Tuesday night's 1-0 win at Coventry City, hot on the heels of a 4-1 victory over Doncaster Rovers has elevated the U's to within seven points of safety, but with a goal difference of -36, that is effectively an eight-point gap.
Mathematically it looks that they would have to win at least five of their final seven games to stay up, and Lions boss Harris will not underestimate the resilience and fighting spirit of a U's side hoping to produce a miraculous escape.
Neil Harris: "I thought we were excellent against Burton on Monday. We produced a proper Millwall performance, which really pleases me, and we have to take every bit of ability and aggression that we showed then into a difficult game on Saturday.
"I saw Colchester play at Coventry on Tuesday and I thought they were really good, especially in the first-half.
"They have some real quality with the football and a desire about them to win games. They will be a much different team to the one we faced at The Den earlier in the season.
"We will have to match the work rate we showed on Monday and need every bit of confidence that we've shown in the last few months to get a positive result."
"They have some real quality with the football and a desire about them to win games. They will be a much different team to the one we faced at The Den earlier in the season.
"We will have to match the work rate we showed on Monday and need every bit of confidence that we've shown in the last few months to get a positive result."
Kevin Keen: "Millwall are going to bring a lot and we know it's going to be a very tough game.
"I came off on the winning side a couple of times (in derby matches playing for West Ham) and scored a winner at Upton Park once. There was always a fantastic atmosphere and they were always proper games, when you were playing against people like Terry Hurlock.
"I came off on the winning side a couple of times (in derby matches playing for West Ham) and scored a winner at Upton Park once. There was always a fantastic atmosphere and they were always proper games, when you were playing against people like Terry Hurlock.
"I've got no doubt that a few of their fans might give me a nice welcome. They certainly would if it was at their place! It should be a really good atmosphere; our players normally respond to that and look forward to it.
"We've both got momentum and it should be a really good game."
Team news
A trio of Millwall players return from international duty this week to bolster Neil Harris' squad for Saturday's match.
Jimmy Abdou (Comoros), Shane Ferguson (Northern Ireland) and David Forde (Republic of Ireland) all re-joined the group in the latter stages of this week having missed The Lions' two matches at Bradford City and Monday's home win over Burton Albion.
Manager Neil Harris has not reported any fresh injury concerns following the Burton game, and instead faces a selection headache of the nicest order.
Skipper Tony Craig enjoyed his first taste of match action since last October with a solid 45 minutes against Bristol City in an U21s Professional Development League game on Monday.
TC continues his steady return to full match fitness with the U21s at Cardiff City on Friday afternoon with a return to the senior squad not yet pencilled in.
Shaun Cummings (knee) remains a long-term injury.
Colchester United boss Kevin Keen is sweating on the fitness of full-backs Joe Edwards and Nicky Shorey, both of whom took knocks in U's surprise 1-0 win at Coventry City in midweek. The duo are rated 'doubtful' but are expected to be available for selection.
Former Lions midfielder Owen Garvan is likely to feature for U's, who also have former Millwall players Matthew Briggs and Sam Walker in their ranks.
Team news
A trio of Millwall players return from international duty this week to bolster Neil Harris' squad for Saturday's match.
Jimmy Abdou (Comoros), Shane Ferguson (Northern Ireland) and David Forde (Republic of Ireland) all re-joined the group in the latter stages of this week having missed The Lions' two matches at Bradford City and Monday's home win over Burton Albion.
Manager Neil Harris has not reported any fresh injury concerns following the Burton game, and instead faces a selection headache of the nicest order.
Skipper Tony Craig enjoyed his first taste of match action since last October with a solid 45 minutes against Bristol City in an U21s Professional Development League game on Monday.
TC continues his steady return to full match fitness with the U21s at Cardiff City on Friday afternoon with a return to the senior squad not yet pencilled in.
Shaun Cummings (knee) remains a long-term injury.
Colchester United boss Kevin Keen is sweating on the fitness of full-backs Joe Edwards and Nicky Shorey, both of whom took knocks in U's surprise 1-0 win at Coventry City in midweek. The duo are rated 'doubtful' but are expected to be available for selection.
Former Lions midfielder Owen Garvan is likely to feature for U's, who also have former Millwall players Matthew Briggs and Sam Walker in their ranks.
Head-to-head
Saturday's game at the Weston Homes Community Stadium will be the 48th meeting between Millwall and Colchester United in all competitions.
It is The Lions who hold superiority in the head-to-head record, winning exactly 50 per cent of those games - 24 - compared to 13 for the Essex club. The remaining 10 games have finished all square.
The most recent meeting in Essex came on Monday 5th April 2010, and it proved a memorable one for The Lions when goals from Steve Morison and Danny Batth (og) secured a 2-1 victory for Kenny Jackett's side.
When we last met
Shane Ferguson bagged his goals in a Millwall shirt as Neil Harris' charges moved to within two points of the Play-Offs when the teams last met at The Den on 21st November 2015.
Lee Gregory opened the scoring for the hosts when he comfortably fired past keeper Jamie Jones before then being denied a second by hitting the post.
Ferguson netted his first on 32 minutes with a low shot, before Colchester substitute Chris Porter struck from inside the box to reduce the deficit against the run of play 10 minutes after the break.
Millwall nearly hit back immediately only for Aiden O'Brien to blast over, but the home team did re-establish their two-goal lead in the 62nd minute when Ferguson found the bottom corner after Gregory played the ball between Tom Eastman's legs.
The pressure was relentless and The Lions netted a deserved fourth goal after 81 minutes when Byron Webster's shot was deflected in to extend their unbeaten run to nine games.
Millwall: Archer, Cummings, Webster, Beevers, Martin, O'Brien (Upson, 78mins), Saville, Williams, Ferguson (Onyedinma, 71mins), Gregory (Martin, 83mins), Morison. Subs not used: Forde, Nelson, Thompson, Romeo.
Scorers: Gregory (13mins), Ferguson (36 & 62mins), Webster (81mins)
Colchester United: Jones, Edwards, Eastman, Elokobi, Olufemi, Gilbey, Bonne, Massey, Moncur, Harriott, Sordell (Porter, 46mins). Subs not used: Wright, Lapslie, Sembie-Ferris, Curtis, Parish, James.
Scorer: Porter (55mins)
Tickets and travel
Lions supporters are reminded that tickets for Saturday's game are now sold out and that it is all-ticket for Lions fans with strictly none available for sale on the day of the game.
There are rail works on the Liverpool Street line for those supporters travelling by train to the Weston Homes Community Stadium. Full details here.
Betting
Millwall are priced at evens for Saturday's Sky Bet League 1 clash with Colchester United, who can be backed at 13/5 with the draw also priced at 13/5.
Lee Gregory is 4/1 to score first or last or 11/8 to score at any time whilst Shane Ferguson, who scored his first two goals in a Millwall shirt in the corresponding fixture earlier this season, is priced at 66/1 to repeat that feat and bag a brace on Saturday.
Maybe you feel that one of Millwall's towering defenders could get on the end of a corner or free-kick during Saturday's match. If so, why not have a punt on Byron Webster (33/1 first or last) or Mark Beevers (22/1 first or last).
Visit Sky Bet for all the latest odds and match specials.
Coverage
All of Saturday's action will be covered with full match commentary on Lions PlayerHD.
Updates from the Weston Homes Community Stadium will also be available by following @MillwallFC - the club's official Twitter account.
Tweets by @MillwallFC