The Red Devils spent over £150m on new signings in the 2017 summer transfer window after Jose Mourinho recruited three players.
Manchester United signed Everton striker Romelu Lukaku, Benfica defender Victor Lindelof and Chelsea FC star Nemanja Matic.
The 20-time English champions are in second place in the Premier League table but a long way behind runaway leaders Manchester City.
Manchester United have been linked with a potential swoop to sign Real Madrid winger Gareth Bale to bolster their squad.
The Red Devils could be facing a tough battle to keep Spanish goalkeeper David De Gea at Old Trafford amid interest from Real Madrid.
Former Liverpool FC striker Bellamy is anticipating that Manchester United will go big in the transfer market in the summer.
“They do need another big window. I am sure Mourinho will demand that,” Bellamy told Sky Sports.
Manchester United signed Alexis Sanchez in a swap deal from Arsenal in the January transfer window.
The Red Devils finished in sixth place in the Premier League table last term but won the EFL Cup and Europa League.
The 20-time English champions could still win the FA Cup this season if the Red Devils beat Tottenham Hotspur to secure a place in the Wembley final.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news