Maguire has started - and captained United - in their two preseason games so far this month as the Red Devils bounced back from defeat to Wrexham to win 5-0 against Rosenborg.
Buoyed by securing UEFA Champions League qualification for the incoming campaign, United have already spent £83M on midfield pair Youri Tielemans and Andrey Santos, alongside free transfer deals for Karl Darlow and Tynan Thompson.
33-year-old Maguire, who signed a one-year contract extension back in April, will be utilised by Carrick in a busy season and the former England international wants to see more new faces before the Premier League returns in August.
"I played with Tielemans for a few months at Leicester and he's going to be an incredible signing. He's Belgium's captain and played the most games for Aston Villa last season. He was a big player there.
"Hopefully more signings are coming through the door. I want a big competitive squad. One that we can go and challenge for the big trophies, so the more the merrier."
United are next in action on August 1st, as they face Atletico Madrid in Stockholm, and their EPL campaign starts against Maguire's old team Hull City on August 22nd.