“In this moment I can’t say anything about it [Højlund’s injury] because I don’t know,” Ten Hag said on Saturday.
“We do an assessment but have to wait for 24 hours to see what the conclusion is. Give them, the medical [team], 24 hours to see what the problem is, if there is a problem.”
A length lay-off for Højlund, who has established himself as United’s first-choice centre forward following his £72 million ($88m) move from Atalanta in the summer, would be a particular blow ahead of a tough run of away games against Everton, Galatasaray and Newcastle United after the international break.
“You don’t want to lose any player and it is the same for Christian Eriksen, but this is also our season, so many injuries,” Ten Hag added.
“So therefore you have a squad. But we talk about it many times, the routine levels in your team, in the way of play. Hopefully the players are coming back and the new injuries are not too bad.”
Højlund is still waiting for his first Premier League goal and before going off, the Denmark international was guilty of missing two golden chances against Luton either side of half-time.
Marcus Rashford, who has scored just one goal in all competitions this season, and Alejandro Garnacho both passed up good opportunities to make the final results more comfortable.
“I don’t think it is particularly a confidence thing because Rasmus Højlund scored five goals in the Champions League and he came full of confidence into this game, it will come,” Ten Hag said.
“Rashford scored 30 goals last season, obviously he’s now not scoring but there will come a day when he starts scoring again. I think the other offensive players, like Garnacho, are capable of scoring goals. But what is good, we already have 13 goalscorers in our team and it expresses the way we want to play football, everyone is attacking, everyone is defending, and also defenders can score goals.”