Chelsea boss Jose Mourinho has spoken highly of Manchester United's progress under Louis van Gaal and believes they will continue to improve.
Mourinho also expressed that he feels to do so, United will spend big once again during the transfer window.
He said: "Man United have a phenomenal squad. They will invest hugely again in the summer."
His views partly crossed over with former Liverpool winger Steve McManaman, who told BT Sport, reported by The Mirror earlier that United need to spend £150 million to compete for the title.
United have pushed Chelsea close this season in their two matches, drawing 1-1 at Old Trafford, and dominating at Stamford Bridge, only to be edged out in a 1-0 defeat.
Mourinho was explaining that he felt Chelsea would not have it easy next season, despite leading the league by 10 points at present with five games to go.
United spent big last summer, buying Angel di Maria for a world record fee, also buying Marcos Rojo, Daley Blind, Ander Herrera and Luke Shaw, and adding Radamel Falcao on loan.
This was done despite a delayed start for Louis van Gaal who joined up in mid-July after his World Cup exploits with Holland, more than a month after Chelsea had laid the blueprints for this year's title success by signing Cesc Fabregas and Diego Costa in early June.
More time, and more knowledge at Van Gaal's disposal, along with potentially a similar pot of money to spend, promises to make United an even more dangerous side next season.