Manchester United manager Sir Alex Ferguson and Arsenal boss Arsene Wenger have both insisted Chelsea will let their Premiership lead slip.
"Chelsea have been carrying a bit of luck but over a season these things even themselves out," said Ferguson.
Wenger said: "I know from experience many teams have been in front in January but not won the championship."
Jose Mourinho's Chelsea are five points clear of Arsenal and nine ahead of Manchester United.
All three teams are in action on Tuesday and Ferguson added: "I think it has been proven that teams can lose their way towards the end of the season because it has happened to us.
"Chelsea know they will drop points. It is how they handle it at the time that matters."
"They have also not suffered the injuries like ourselves and Arsenal have."
Wenger said that Chelsea face different problems leading the table from those sitting below them in the table.
"That is a difficult psychological challenge to deal with when you leading, especially when the chasing clubs behind you are strong," said the Gunners boss.
"When you are in front and everyone says you have already won the title you have to face up to the prospect that you can only lose it from there.
"If you watch Chelsea's recent games it looks as if it has not been so easy for them.
"They had the decisions going for them at Liverpool on Saturday but I am surprised to see so many people have already declared them as champions."