Jose Mourinho says any injury to Zlatan Ibrahimovic would represent a "disaster" for Manchester United.
The 35-year-old has impressed for United since signing from Paris Saint-Germain on a free transfer, playing in 17 of United's 18 Premier League matches and scoring 12 goals.
Mourinho has been consistent in his praise for Ibrahimovic since his move and had kind words for the striker again ahead of his side's home match against Middlesbrough on Saturday.
The manager also suggested Ibrahimovic has to work harder for his goals in England than the likes of Lionel Messi and Cristiano Ronaldo have to do in LaLiga.
"A disaster," Mourinho told reporters after being asked how bad an injury to Ibrahimovic would be.
"Obviously it would be a disaster, but that is football. [The goals he has scored] are not a surprise.
"In Spain, Messi and Cristiano [Ronaldo] have a lot of penalties to score. They are phenomenal players with lots of penalties to score goals.
"Here, Zlatan has 18 matches and one penalty. It is not so easy to score goals."
Despite being concerned about what would happen should United lose Ibrahimovic, Mourinho does not plan to sign another striker in January.
"We are not going to do that," he said.
"We have Zlatan, Rooney, Rashford and Martial, who can also be a number nine in a different style.
"We have a squad of 24 players. I know we have a lot of competitions to play but where is the striker to come here with that quality to play for United?
"Where is that striker, where the club can let him come?
"That is not something for the January market, it is probably something for the summer."
