The vice-captain suffered an injury in the closing stages of last month’s 4-2 win over Manchester City and has subsequently missed the Reds’ three consecutive defeats against Chelsea, Everton and West Bromwich Albion in the Barclays Premier League.
The good news is that Luke Shaw is available to face Crystal Palace on Saturday after recovering from the slight problem that kept him out of the match against the Baggies. Jonny Evans is also available, although the boss says he doesn’t have “match rhythm”.
"Carrick is not available, it was more heavy than we thought," van Gaal told MUTV. "We tried everything but now we have to think about next season. He shall not play anymore this season, it's better now to focus for him on next season and being fit to start.
"When you see the stats, it's clear that he's very important but that's also because we have only right-sided holding midfielder. That's what I am saying already in the whole of the season, that our selection is not balanced, and I want to restore that in the next transfer period. The life is not ending at 34, but for a professional football player, it's close by. That's why I have to handle again in that position."
On other injuries, the boss said: "Evans and Shaw can play football or the game. Evans doesn't have the match rhythm as he was injured for six weeks and after that he was suspended for six weeks, and after that he was injured. He needs match rhythm."
Meanwhile, Marcos Rojo is on his way back to full fitness and James Wilson could be among the substitutes after recovering from illness. "There is a virus in our dressing room so it's difficult to say," revealed van Gaal. "He is already a little bit ill for one week but now he is recovering so I think he could be on the bench."
To see the full exclusive interview with Louis van Gaal, watch The Manager's Press Conference show at various times on MUTV including 14:00, 16:00, 18:30 and 22:30 BST. MUTV subscriptions are available on Sky | Virgin Media | UPC.
More: Live blog: Press conference | Match centre: Palace vs United