Manchester United boss Louis van Gaal has piled the pressure on Leicester City and Tottenham, claiming there will come a time when the inexperienced title-challengers "have to win."
With 13 matches remaining, Leicester and Spurs are the Premier League's surprise top two, with the Foxes five points clear and Spurs ahead of rivals Arsenal on goal difference and one point ahead of Manchester City.
Tottenham face City at the Etihad Stadium on Sunday following Leicester's match at Arsenal.
Meanwhile, Van Gaal's United are in fifth, 12 points from top, but they will close the gap on the top four with a victory at Sunderland on Saturday.
Between them, Leicester and Spurs boast one player with experience of winning the Premier League titles -- Foxes centre-half Robert Huth -- and Van Gaal, a serial champion with Ajax, AZ Alkmaar, Barcelona and Bayern Munich, has warned that the pressure to win games will significantly increase as the finish line approaches.
"They [Leicester] are the favourites because they are five points away from the rest, but the moment that they have to win it is different," Van Gaal told The Independent.
"They are more or less in that place now because they want to continue with this lead.
"Is it possible? Why not? Maybe their players can cope, but that you do not know and that is a question that both Leicester and Tottenham must answer.
"It doesn't say anything about the personalities in these teams. I don't know them so I cannot judge. But there shall come a moment when they have to win. At the moment, everything is OK and nice. But the manager has spoken about being champion, so now it shall play in their heads. But a lot of players can cope with that."