Sir Alex Ferguson says there will be no complacency at Old Trafford despite the eight-point gap Manchester United enjoy over Chelsea at the Premiership summit.
"I won't be letting the players fall into the trap of thinking it's won," said Red Devils manager Ferguson.
"All we have done is given ourselves a foundation. There are many hurdles to be navigated in the run-in.
"That will be the test for us. I'm sure it will be ourselves and Chelsea, but I'm sure we will last the distance."
Having drawn at home to Arsenal, Chelsea boss Jose Mourinho is confident his side will get back to winning ways when Newcastle travel to the capital on Wednesday.
Victory against the Magpies would cut the gap at the top to five points and Mourinho has said the Blues are ready to fight to the last.
"If Sir Alex Ferguson thinks it's over he's in trouble, because it's not over," he said after the 1-1 draw against the Gunners.
"I think after Wednesday we will be five points behind and what is five points in a long Premiership season?"
Ferguson has landed eight Premiership titles in his 20 years at United and experience tells him December is too early to start lauding potential champions.
"To win the league, you have to have great consistency, particularly around March and April," added the Scot.
"Historically, we have done okay at that time of the year.
"All championship races are difficult, but the real test comes on the run-in when any mistake can cost you everything."
Chelsea are scheduled to host United five games from the end of the season in mid April.