JOSE Mourinho fears the worst after Zlatan Ibrahimovic and Marcos Rojo were forced off with serious-looking injuries as Manchester United reached the Europa League semi-finals.

Both are set to miss United's trip to Turf Moor tomorrow after the pair where taken off injured during Thursday night's 2-1 extra time win over Anderlecht.

Rojo left the field on a stretcher in the first half, before top scorer Ibrahimovic's knee buckled after landing awkwardly just before extra-time.

Asked about the condition of the pair, Mourinho said: "I want to wait, but my feeling is not good for both.

"I want to wait and try to be optimistic, but I am not."

Ibrahimovic was able to hobble off after the injury and Rojo told reporters he was "okay" while limping heavily through the post-match mixed zone.

The Argentina international, so impressive this term, is another blow to a defence already without Phil Jones and Chris Smalling.

Mourinho last week said the England centre-backs were out until mid-May, but suggested after the Anderlecht win that they need to be "brave".

"We have Daley Blind, who has experience in the position, and I think it is time for Jones and Smalling to be brave - to risk," the United boss, who seemed to criticise Smalling's pain threshold earlier in the season, said.

"Because for the team you have to do everything, that is the way I think.

"You cannot do miracles, so miracles I don't expect, but they have to try to do everything to accelerate the process.

"They have injuries, and even with a crazy mentality, they cannot play Sunday (at Burnley in the Premier League).

"But with a special spirit, you can (come back) sooner than expected. So instead of mid-May, it could be the beginning of May, this kind of acceleration of the process."