Manchester United manager Sir Alex Ferguson says it is wrong any team should have to play early on a Saturday after a midweek European tie.
United played Arsenal in the Champions League on Wednesday and live television coverage means they face a 1245 BST kick-off at Middlesbrough on Saturday.
"You'd think people in offices think about it but when you shake hands with the devil you pay the price," he said.
The game at Boro is likely to have big implications at both ends of the table.
United, three points clear at the top of the Premier League with five games left, hope to cement their lead before title rivals Liverpool - who host Newcastle - and Chelsea, who face Fulham, play at 1500 BST on Saturday.
Middlesbrough, meanwhile, are three points adrift of safety and fighting to avoid the drop into the Championship.
Ferguson admitted with so much riding on every game, it was hard for anything to be regarded as a priority.
"Every game is so important and the incentives so great now, whether it is at midnight or 7am, it does not interrupt what we are doing," he said.
After Wednesday's 1-0 first-leg semi-final win over Arsenal, Ferguson is expected to make changes and rest players, but has hinted he may not make as many changes as first thought.
"The funny thing is the players are quite buoyed up and want to play," said Ferguson.
"Our performance on Wednesday helps, although I have to make sure there is the right kind of freshness so we get the balance in the team right.
"I have plenty of fresh players. Ryan Giggs only played for 20 minutes on Wednesday and Paul Scholes is fresh."
Ferguson also has Wes Brown available for the first time since the end of January.
Brown may be required if Jonny Evans, a likely replacement for the injured Rio Ferdinand, fails to shake off a foot problem.
Boro, meanwhile, are still missing defenders Emanuel Pogatetz (knee) and Chris Riggott (ankle), but French midfielder Didier Digard - who came on during last week's 2-0 defeat by Arsenal - is in contention for a start.
Manager Gareth Southgate has admitted failing to stay in the Premier League would affect a lot more people than just the playing staff.
"What always happens in any club that is relegated, people who aren't earning very much are often the ones who lose their jobs, and that's unsettling for everybody," he said.
"I want to achieve success over the next few games for everybody at the club, not just the players.
"As the manager, you have to prepare for both scenarios. I have to plan budgets and look at the upheaval."
Despite their parlous position, Southgate remains upbeat about causing an upset against United at The Riverside.
"We have got results against Arsenal and Liverpool here this season already, so that fills us with confidence," he added.
"There's nothing to lose because nobody would expect us to get anything from the game - and if we do, that's a huge boost for us."
Middlesbrough (from): Jones, Turnbull, Hoyte, McMahon, Taylor, Grounds, Wheater, Huth, Hines, Aliadiere, Tuncay, Bates, O'Neil, Walker, Shawky, Downing, Johnson, Digard, Alves, King.
Man Utd (from): Van der Sar, Foster, Kuszczak, O'Shea, Rafael, Brown, Vidic, Evans, Evra, Ronaldo, Nani, Scholes, Fletcher, Carrick, Anderson, Park, Giggs, Rooney, Tevez, Berbatov, Macheda, Welbeck.