Man Utd boss Ruben Amorim 'really concerned' as Brentford defeat goes from bad to worse

head coach admitted he was "really worried" about Matthijs de Ligt after the defender limped off in . De Ligt made his first start since the 1-0 loss at Nottingham Forest on April 1 but lasted just 35 minutes after going to ground in the build-up to Brentford's second goal.

He returned to action off the bench in United's 3-0 victory at Athletic Club on Thursday, handing Amorim a monumental boost in pursuit of Europa League glory. However, the sight of De Ligt hobbling down the tunnel in the first half struck as much fear in the dugout as it did among supporters. And after the final whistle at the Gtech Community Stadium, Amorim couldn't offer a positive update on his fitness, sharing fears the injury could even impact plans for next season.

"I don't know [how serious De Ligt's injury is], so I'm really concerned - not about Thursday," Amorim explained to Sky Sports.

"We took off Luke Shaw at half-time to protect and have players for Thursday, but I'm more concerned whether it is a small or big injury and thinking about next season."

In an interview for BBC Match of the Day, the Portuguese tactician added: "I don't know. We will see.

"I hope it's nothing serious. We took a risk with Maguire. Shaw had to go out because we need players for Thursday."

De Ligt was reportedly spotted limping as he left the stadium but was unaided and didn't require crutches. However, the Dutchman is now a doubt for Thursday's Europa League semi-final second leg.

Amorim made eight changes from Bilbao against Brentford, naming the youngest United team in Premier League history.

Mason Mount fired the visitors ahead before a Luke Shaw own goal, Kevin Schade brace and Yoanne Wissa strike made it 4-1 with 16 minutes remaining.

Alejandro Garnacho's long-range stunner and Amad's first goal since his return from injury - alongside De Ligt against Athletic Club - teased a late comeback but weren't enough.

Despite tasting United's 16th Premier League defeat of the season, a result that confirmed a bottom-half finish, Amorim insisted he could see signs of progression.

He said: "I have no doubt that we are playing better. So we have to take all the heat. At this moment, we are losing games in the Premier League.

"We are fighting for the Europa League and Thursday is the most important game for us. I think it's stressful to lose games. When we're fighting for a title [trophy], it's not stressful."

United will face Tottenham Hotspur or Bodo/Glimt in the Europa League final if they avoid their latest capitulation against Athletic in four days' time.