Premier League champions Chelsea remain the team to beat, despite Manchester United's activity in the transfer market.
Manchester United have recruited heavily as manager Louis van Gaal prepares for his second season in charge, but former captain Roy Keane doubts whether his former club can overtake Chelsea.
It has been another pre-season spending spree at Old Trafford, with Van Gaal investing heavily to sign Memphis Depay, Morgan Schneiderlin, Bastian Schweinsteiger, Matteo Darmian and Sergio Romero.
The quintet's arrival comes after Ander Herrera, Luke Shaw, Marcos Rojo, Daley Blind and Angel di Maria were brought to the club last season, though the latter is poised to join French champions Paris Saint-Germain.
Keane, however, still believes United are lacking the necessary personnel to trump Chelsea in the Premier League race, having finished fourth last term.
"United have gone away from what they were about; they are a bit like the late 80s, buying a lot of players thinking they will gel but it doesn't happen that quickly, as much as they'll definitely be stronger this year," Keane told the Sunday World.
"Van Gaal's had a full pre-season this year. They've looked good from what I saw in pre-season, but they had a good pre-season last year too."
Keane added: "I don't think the spine of United is strong enough, I still think they need a centre-half maybe. United will no doubt be better next year, they'll need to be stronger out of the blocks, but if I was a betting man, which I'm not, I'd still go with Chelsea.
"Chelsea are the team to beat; with the strongest spine. I think they're after the boy [John] Stones too, and if they add him, if Chelsea players show the same hunger and desire they did last year, they'll win the league.
"Mourinho has good players, bloody good players. It looks like he's got a good spine to the team, John Terry, their goalkeeper, the couple of lads in the middle of the park, Diego Costa, [Radamel] Falcao and Eden Hazard too."