Paul Pogba, a newly crowned world champion, will need a holiday after his exertions in Russian Federation, and Mourinho has already suggested the midfielder will not be ready for the opening game of the Premier League season against Leicester at Old Trafford on August 10.
Chong played a part in United's equaliser during the 1-1 draw with Club America and while Mourinho acknowledged that the 18-year-old is still developing, there were words of encouragement for the Dutchman.
Chong left Feyenoord's academy for Manchester United in 2016.
"If he can play like today, 20 or 25 minutes in every one of these five matches and if during the season he trains with us and has a couple of occasions to play minutes with us, I don't know, depends on some cup matches, he is one of the good kids we have".
It has been an uncertain summer for Martial, whose agent, Philippe Lamboley, has been vocal about the 22-year-old's desire to leave Old Trafford.
Four minutes later the Frenchman fired a curling shot over the crossbar, and United came close again minutes later as Mata loosed a shot that bounced off the upright.
The Portuguese, though, will still be without Paul Pogba, Romelu Lukaku, Marouane Fellaini, Marcus Rashford, Jesse Lingard, Marcos Rojo, Phil Jones, Victor Lindelöf, and Ashley Young even when De Gea, Matic, and Fred follow Sanchez.
Lee Grant's debut in United's goal was marked by a sharp save from Roger Martinez when the No9 ran through.
Shaw featured in 23 games for the Red Devils last season and will look to play as much as possible in the upcoming campaign.
And they're set to splash more cash with Jose Mourinho eager to add to his defensive, midfield and attacking options.
Jose Mourinho was impressed by Dutch teenager Tahith Chong.
Just before the hour the 'keeper could do nothing to stop Club América's Henry Martin as he rose and headed sweetly past him for the opener, Antonio Lopez delivering the cross. His inviting cross from the right was headed onto the post by Ander Herrera, only to eventually fall to Mata to turn home.