With almost a fully fit squad at his disposal- but with Marouane Fellaini now suspended- Van Gaal said fatigue, rather than fitness, will be key when it comes to selection at Carrow Road on Saturday.
"We have to look after the tiredness of the players because there's an overload of matches so maybe I have to rotate also, and now Fellaini is suspended so I have to change my line-up.
"It is always difficult to play against a team who are fighting to maintain their position in the Premier League- that is always very difficult but we have to cope with that" said the Dutchman.
United's impressive performances against the league's leading lights are a source of frustration when set against less laudable efforts this term- one of which was the 2-1 defeat in the reverse fixture shortly before Christmas- and Van Gaal lamented what might have been.
"When you see what we have against the top five, what we have done against the bottom five is not a good average and the month of December caused us big damage and that was not good."
"They (Norwich) won at home, at Old Trafford, so we have to take revenge- it shall be a very tough game but in spite of that we have to win" added the boss.
Recent wins over West Brom and fellow strugglers Newcastle looked to have boosted the Canaries hopes of avoiding the drop, but Alex Neil's side have since lost three on the bounce and come into this one deeply rooted in the relegation mire following promotion last term.
In a congested scrap, Norwich sit second bottom but only two points from safety in a survival fight that looks likely to go the wire with Newcastle and Sunderland also scrapping for their top flight lives.
This looks a decisive fixture for both: should Norwich lose then it would surely spark an immediate return to the second tier whilst defeat for Van Gaal's side and- for seemingly the umpteenth time this season- our top four hopes would be all but over.
As well as Belgian Fellaini, who begins a three-match ban (he will be available for the Cup final), long term absentees Bastian Schweinsteiger and Luke Shaw remain sidelined for the visitors whilst Alex Tettey (whom scored in that game at OT) and Timm Klose miss out for Norwich.
Match odds: Norwich 19/5 Draw 20/12 United 6/4
Referee: Craig Pawson