Manchester United number two Carlos Queiroz insists that The Red Devils are looking to emulate their treble success of 1999.
Sir Alex Ferguson's side are desperate to recapture the Premiership crown they have gone without since 2003.
"It's not enough for us to compete only for the league," he told United Radio.
"We also have ambitions and a great desire to win the other competitions as well.
"The reality at the moment dictates that the championship will probably be a two-horse race.
"But that isn't the case when it comes to the FA Cup and Champions League - it's wrong to think those competitions are also between us and Chelsea."
Queiroz also feels that United cannot think that the title is already won.
"We deserve our position because we're playing the best football in the league at the moment and all the lads are doing very well," he said.
"But we haven't won anything yet though. We're in a good position as a result of our hard work, commitment and concentration and we must keep that going until the end of the season.
"The race will not be easy and I'm sure Chelsea will not give us any chances to make mistakes.
"We cannot just enjoy the fact that we're six points clear, we need to build on that.
"If we don't, then that is when you make mistakes and one small mistake could represent big punishment for us.
"Letting our focus and our state of alertness slip even just a little bit is the wrong attitude for us."