Manchester United head coach, Ole Gunnar Solskjaer says his team's fixture schedule over the coming week is "physically impossible" after his side reached the Europa League final.
United lost 3-2 to Roma but emerged 8-5 aggregate winners in the semi-final and will now meet Villarreal on 26 May.
Thursday's game in Rome was the first of four matches in eight days.
"It's unheard of," said Solskjaer after reaching his first final as United boss.
Speaking for the first time since learning United will have to play league games on Sunday, Tuesday and next Thursday, Solskjaer added: "It's made by people who have never played football at this level.
"It's physically impossible for the players.
"We are going to need everyone for these four games. It's a short turnaround but we have to be ready."
United, who are second in the Premier League, are away to Aston Villa on Sunday (14:05 BST).
