Jose Mourinho's Blues are unbeaten after seven league games this season - and currently sit top of the table.
United, meanwhile, are in fourth despite a bad start to their league campaign. Three wins in four have rocketed them up the standings.
And, as far as Keown is concerned, that is how things could remain come the end of the season.
"Can Chelsea do it? Yes they can. It’s a hell of a long way to go and they have to hope people stay fit for the duration," Keown said as part of a Tackle Keown session on the Daily Mail website.
"It’ll be interesting to see how many of their players play for their countries in the international break.
"Jose won’t want to share his players when things are going so well at the moment. But you have to admire what they are doing.
"Jose just has to be careful, because sometimes when his team do all the talking on the pitch, he does even more off it. He can have that sense of bitterness running through him and that makes it harder for neutrals to appreciate what they are doing."
On Man United, meanwhile, Keown said:
"United have snuck into fourth position with barely anybody noticing. If they had won the Leicester game they would actually be in good shape! We have all been critical of them but they are not doing too badly
"I tipped them at the start of the year to nick a Champions League position and now they look better equipped with the new signings they have made."