Manchester United XXXX Brentford in the Premier League on Sunday but now their attention will turn to the Europa League . Two goals from Bruno Fernandes and a Casemiro header have put United in control of their semi-final tie with Athletic Bilbao. The two teams will meet again on Thursday at Old Trafford, with United in pole position to reach the final of the competition. Should they get the job done and qualify for the Europa League final, they look set to face Premier League rivals Tottenham in Bilbao on May 21. Spurs are 3-1 up at the halfway point of their semi-final clash with Bodo/Glimt. Ahead of United's clash with Ernesto Valverde's side, here is the very latest on the injury front... Injury: unknown Matthijs de Ligt had to be taken off in the first half of United's Premier League clash with Brentford. The Dutchman entered into a 50-50 challenge with Yoane Wissa before signalling that he had picked up a knock. He had to be replaced by Harry Maguire. When asked for an update on De Ligt's situation after the game, Amorim said: "I have no idea. He could be training in three days, for all I know." Possible return date: unknown. Injury: calf Dalot has missed the last three matches after Ruben Amorim confirmed he had suffered a muscle injury in the 1-0 defeat to Wolves on Easter Sunday. Amorim said the defender will miss United's upcoming matches, and it remains to be seen if he will be back available before the end of the season. The United head coach said: "He has something in his muscle, his calf, he had a sequence of games, he played all the time, we try to manage but the players play a lot of minutes and not so ready to cope with that. Dalot felt something. "We don't know how long he's going to be out. But he's out for these next games." Possible return date: unknown. Injury: knock After missing United's first three games after the March international break, Heaven returned to the squad against Newcastle United on April 13, being named on the bench However, he has not featured in any of United's matchday squads since then after suffering a "small setback", according to club sources. Issuing an update recently, Amorim said: "Ayden is not ready, so that's it." Possible return date: unknown. Injury: anterior cruciate ligament (ACL) Martinez is a long-term absentee after rupturing his ACL in United's 2-0 defeat to Crystal Palace at Old Trafford at the beginning of February. He soon underwent successful surgery and is well underway with his recovery. United have not put a specific timeframe on how long he will be out for, but he will not feature again this side of the summer. ACL injuries usually take around six months to fully recover from. Possible return date: August. Injury: leg Collyer was spotted training at Carrington on Wednesday morning, albeit away from the main group, offering positive signs that his recovery is going well. He could be back for the second leg against Bilbao. Possible return date: Athletic Bilbao (Thursday). Injury: hamstring. Zirkzee was forced off with a hamstring injury in United's 4-1 defeat to Newcastle. He required medical attention before leaving the pitch. He was able to walk off the field, but he required help from two members of the United medical team. Unfortunately, he will now miss the remainder of the season. "Joshua is out for the season, so he's not going to play any more this season," Amorim said. "Let's prepare him for the next one." Possible return date: pre-season.