Man Utd legend Gary Neville feels that former club need to sign at least four-or-five players this summer if they want to compete on multiple fronts next season.
The Red Devils have already signed Victor Lindelof and Romelu Lukaku this summer, and according to the latest reports, they are now pursuing deals for the likes of Inter Milan's Ivan Perisic and Chelsea's Nemanja Matic.
"United need to strengthen, but they all do - quite a bit," he said on Sky Sports.
"Even the champions need to if they're to repeat what they did last season.
"You're not just talking about winning the Premier League title, you're talking about competing in Europe.
"English clubs have been well short in the last few seasons.
"All big clubs want to be winning Champions Leagues.
"That won't happen unless they significantly improve. United need to sign four or five players."