Erik ten Hag will oversee a team of youngsters as United take on Wrexham in San Diego overnight on Tuesday and, just 24 hours later, a more experienced lineup will take on the Spanish giants.
Last week, the club announced the £47.2million signing of Cameroon international Onana, 27, to replace David de Gea. The former Ajax shot-stopper being reunited with manager Erik ten Hag.
Elsewhere, Anthony Martial is yet to feature for United in pre-season as he continues to recover from the hamstring injury sustained in the FA Cup final defeat to rivals Manchester City last month.
Ten Hag said on Tuesday: “Today, he was in the team training; that is really hopeful. Of course, when you have a player in your squad, you expect he is available and players have to take responsibility.
“If not, I have to deal with the situation and we have shown we can be successful without that striker.
“But it’s easier when you have that striker in the team, I think every club who wins big trophies has scoring abilities in their team.”
Man Utd predicted XI: Onana; Wan-Bissaka, Varane, Martinez, Shaw; Casemiro, Mount, Antony, Fernandes, Pellistri; Sancho
Doubts: Martial, Amad
Time and date: 3.30am BST, Thursday, 27, 2023
Venue: NRG Stadium