Jose Mourinho believes that Manchester United’s success in cup competitions this season could leave them “in trouble” as their campaign progresses.

Thursday’s Europa League last-32 first leg meeting with Saint-Etienne commences a run of four straight cup fixtures for United, including an EFL Cup final against Southampton at Wembley.

Progression past Blackburn Rovers in Saturday’s FA Cup fifth round tie, meanwhile, would mean Mourinho’s men play just one Premier League fixture in the next month.

The Portuguese is concerned that fighting on all fronts could leave his squad on the back foot in the tight race for a place in top four and consign United to another year in European football’s secondary competition.

“We cannot choose the competitions at Manchester United," the United boss said ahead of Saint-Etienne’s visit. “We know that our situation is really complicated.

“We know that the Europa League is also a competition where we play on Thursdays and that makes it even more difficult for us. The accumulation of FA Cup, League Cup, match postponements is really hard for us.”

He added: “If we progress in the competitions, we will be in trouble in April and May. But we cannot choose competitions, so we play them to win.

​“I think it's also a good way to give the team experience and international experience is always a plus. Europa League is not a competition we want to play, but it's a competition we play and we respect it.”

Nevertheless, Mourinho promised “go seriously” when selecting his starting line-up for Thursday’s first leg and Saturday’s trip to Ewood Park.

Luke Shaw will play no part against Saint-Etienne, missing out on the match day squad for the fourth consecutive fixture. Wayne Rooney and Michael Carrick will be rested, but Paul Pogba is set to start.

The world’s most expensive footballer will come up against his elder brother, Florentin, who makes up part of Ligue 1’s second-best defence this season.

“We spoke in a good way, a funny way,” Mourinho said of Paul, ahead of the siblings’ meeting. “I think it is a good, nice destiny.

“I think only mum Pogba is a little bit in trouble, which is normal. It's difficult for the lady to choose - it's not difficult, it's impossible!

“I know from Paul that the mum wants a draw, but next week one son will be happy and another one will be sad.”