Manchester United midfielder Michael Carrick has been ruled out for the rest of the season with a calf problem, Louis van Gaal has confirmed.
Carrick's injury, which he sustained in the 4-2 win against Manchester City on April 12, has proved far worse than was first feared.
However, United defenders Luke Shaw, Jonny Evans and Marcos Rojo are back in contention for the Premier League clash at Crystal Palace on Saturday.
United have won 12 of the 16 league games Carrick has started, but only seven of the 19 he has not, and Van Gaal has admitted his absence is a blow.
"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 one right-sided holding midfielder."
Van Gaal added that Carrick's injury shows why he needs to buy a new midfielder in the summer transfer window.
"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," he said. "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."
Shaw missed last week's 1-0 defeat to West Bromwich Albion with a groin problem but is now back in contention, while Evans has not figured in United's last eight games after serving a six-match ban for spitting at Newcastle's Papiss Cisse, before then suffering from sciatica. Rojo, meanwhile, has not featured since the win over City but has since overcome an adductor injury.
Van Gaal added: "Evans and Shaw can play football or the game. Evans doesn't have the match rhythm because he was injured for six weeks and after that he was suspended for six weeks, and after that he was injured.
"Evans is a candidate for the bench but he needs match rhythm. Rojo is coming back but [I may] put him on the bench or something like that."
Phil Jones is also closing in on a comeback following an ankle injury and played 62 minutes for United's under-21 team in the 1-0 win against Southampton on Monday.