“You can see we haven’t played games at this level for a while,” Ole Gunnar Solskjaer, interim manager of Manchester United, admitted last month after the team was beaten by Paris Saint-Germain in the Champions League, Europe’s most prestigious club football competition.

Mr Solskjaer was an emergency hire after  José Mourinho was sacked by the Premier League club in December — the latest coach to be dismissed during a five-year period of decline for a team that once dominated English football. Although Mr Solskjaer has inspired a remarkable recent run, the loss to PSG was a “reality check” on the team’s ambitions to challenge the continent’s best.

The two clubs will meet again on Wednesday in the second leg of their round of 16 tie, and Mr Solskjaer insists a famous comeback is still possible. “Mountains are there to be climbed,” he said.