Son Heung-min has travelled with Tottenham Hotspur's squad and is set to play some part against Manchester United on Sunday.
Son came off at half-time in Tottenham's 1-1 draw with Newcastle last Sunday after sustaining a hamstring injury.
The South Korean forward has missed Spurs' two games since in the Carabao Cup and Europa League.
Mourinho was asked again on Thursday night for the latest on the attacker's fitness.
"I don't want to lie to you and say he doesn't play and Sunday he's there," he said.
"At the same time I don't want to say he plays and then he doesn't. So let's wait and see, in this moment, I honestly don't know."
Despite the initial concerns last weekend, it appears Son has recovered quicker than expected and according to our colleagues at the MEN, the 28-year-old has travelled with the Spurs squad to Manchester.
New Tottenham signing Carlos Vinicius was also spotted arriving with his new teammates after joining Spurs on a season-long loan from Benfica.
According to the MEN, the Spurs players who were spotted arriving were: Hugo Lloris, Joe Hart, Paulo Gazzaniga, Toby Alderweireld, Davinson Sanchez, Ben Davies, Sergio Reguilon, Eric Dier, Harry Winks, Pierre-Emile Hojbjerg, Tanguy Ndombele, Gedson Fernandes, Moussa Sissoko, Lucas Moura, Erik Lamela, Carlos Vinicius, Dele Alli, Son Heung-min, Harry Kane.
