Manchester United's new signing Yoro returns to team training after injury layoff
Having picked up the injury during a pre-season 2-1 friendly loss against Arsenal in Los Angeles in July, the 18-year-old Frenchman underwent successful foot surgery in early August.
United had signed the highly-rated youngster from French club Lille on a contract until June 2029, with the deal reportedly worth around 62 million euros ($66.36 million) and eight million in add-ons.
"He's been managed very well since his injury in pre-season. We knew it would be a long one. It's a big moment for him, that first time he is back in team training," Van Nistelrooy told reporters ahead of Thursday's match at Old Trafford.
"Obviously we will get him back partially over the coming weeks and look to get him back as quickly as possible."
The former United striker, who is taking charge after the sacking of fellow Dutchman Erik ten Hag, was also asked about his future at the club.
United announced the appointment of Portuguese Ruben Amorim last Friday. He will arrive from Primeira Liga club Sporting on the 11th of November on a contract until June 2027.
Amorim marked his final home game as coach of Sporting in stunning fashion as his side beat reigning Premier League champions Manchester City 4-1 in the Champions League on Tuesday.
"It's difficult to comment on that now, I am waiting for conversations to take place," Van Nistelrooy said on his future.
"In the meantime, the most important thing is getting the work done on a daily basis and in the game tomorrow in Europe. I have to say that I feel the responsibility to do well over the next week and that is my job. I am focused on that.
"I welcome Ruben, I am happy to help him and that is the situation at the moment."