Jose Mourinho has hinted Manchester United may be forced to enter the transfer market during January because of the club's growing injury list.
At present, United have nine first-team squad members on the treatment table, including Zlatan Ibrahimovic, Antonio Valencia and Marouane Fellaini - the latter has not featured for five weeks.
When asked if he would be adding new players to the squad this month, Mourinho told Sky Sports: "Honestly, I don't know.
"At this moment we are in trouble. In two or three weeks' time, if we recover some players, maybe we breathe in a different way.
"Do we improve the team now or wait until the summer? I cannot say."
The United boss was speaking following their 2-0 victory over Everton on New Year's Day, which moved them 12 points behind runaway Premier League leaders Manchester City.
Second-half goals by Anthony Martial and Jesse Lingard earned United a first win in five games in all competitions.
Mourinho previously said he was unlikely to add any new players to his squad in January, but United's injury list appears to have altered his stance.
He said: "Nine players were not here. I always say that I like my guys very, very much. We have a fantastic relationship, we give our best, we try to do well always and when we don't we stick together and fight.
"If somebody comes, welcome, if nobody is coming we are going to fight with the players we have.
"I had not one more player to select, even Chris Smalling was on the bench but he could only play in an emergency situation."