Manchester United manager Jose Mourinho said he "doesn't know" when forward Anthony Martial will link up with the squad after his side beat Real Madrid 2-1 in the International Champions Cup.
Goals from Alexis Sanchez and Ander Herrera earned United a first 90-minute win of their United States trip, but they had to do without Martial in Miami after he left the tour last week to be at the birth of his daughter.
Mourinho questioned why the France international did not return for Saturday's 4-1 defeat by Liverpool.
Asked if Martial would be part of his squad for Sunday's game against Bayern Munich at the Allianz Arena - five days before the start of the Premier League season - he said: "I don't know."
Martial has been linked with a move from Old Trafford and it is understood the club would be willing to let him leave for a team outside the Premier League.
Mourinho did confirm attackers Marcus Rashford and Romelu Lukaku and defender Phil Jones had volunteered to return to training three days early in a bid to ensure they are fully fit for the Premier League opener against Leicester on 10 August.
Chile forward Sanchez impressed against Real in the final match of United's five-game trip, scoring their first goal and creating the second when he nodded Juan Mata's cross into the path of Herrera, who finished with a first-time shot.
Summer signing Fred started in midfield, while goalkeeper David de Gea returned to the team.
Gareth Bale started for Real but his only chance of note was a curling shot that went wide.
Karim Benzema, the only player who began the Champions League final win over Liverpool to start in Miami, pulled one back in first-half stoppage time.
Man Utd: De Gea; Darmian, Bailly, Fosu-Mensah, Shaw; Herrera, Fred (Tuanzebe 68), McTominay (Mitchell 79); Mata (Garner 82), Alexis, A Pereira.
Subs not used: Grant, J Pereira, Williams, Hamilton, Gomes, Chong, Bohui, Greenwood.
Real Madrid: Casilla (Lunin 46); Odriozola (Sergio Lopez 62), Vallejo (Nacho 77), Sanchez, Hernandez (Reguilón 46); Llorente (Asensio 77), Valverde (Isco 77); Bale (Odegaard 46, Kroos 77), Ceballos (Raul de Thomas 62), Vinicius Junior (Oscar Rodriguez 62); Benzema (Mayoral 46).
Subs not used: Navas, Carvajal, Vazquez, Bernal, Zidane, Franchu, Seoane, De la Fuente.