Cole won the Premiership, FA Cup and Champions League at Old Trafford in 1999.
He said: “Winning the Treble was the best moment of my career because you never expect to achieve anything like that.
“A lot of people said it was impossible to win all three trophies so it was fantastic being part of a great team like we had.
“Since 1999, the likes of Arsenal, Chelsea and even Man United have aspired to repeat it because it is such a unique thing to do. But if anyone can do it again it would be United.”
Cole added: “The side now is very different from the one I played in. We were very much a team and everyone played for each other – now they have some fantastic individuals.
“Rooney and Ronaldo are great talents and great individuals and, with players like them in your side, there is always a chance.
“They are favourites to win the Premiership, are in the last 16 of the Champions League and always seem to do well in the FA Cup.
“You need a bit of luck to do the Treble and we definitely had that – so who knows? I think it is possible because Alex Ferguson has built another great team.
“Everyone wrote him off a couple of years ago but that is a dangerous thing to do because he loves proving people wrong.”
