The centre-back is yet to make his official debut for the Red Devils, having suffered a fractured metatarsal on just his second non-competitive appearance for the club during pre-season.
Yoro, 18, trained on Wednesday morning ahead of Thursday's Europa League clash with PAOK, though, and Van Nistelrooy has provided a positive update on the defender's fitness.
"He's been managed very well after his injury in pre-season," Van Nistelrooy told reporters."It was obviously going to be a long one. Big moment, first time back in team training. He'll be back partially over the coming weeks and we'll look to get him on board as quick as possible."
There have been suggestions that Yoro's debut for the 20-time English champions could come against Arsenal at the start of December, but Man United will not be taking any risks when it comes to the wonderkid's fitness.
Malacia "is the furthest at the moment"
Van Nistelrooy also addressed Tyrell Malacia's situation, with the Netherlands international recently returning to training as he attempts to overcome the serious knee injury which has sidelined him since the 2022-23 campaign.
Man United's interim head coach said that Malacia "is the furthest" in terms of the players currently battling to be available, with Harry Maguire and Luke Shaw not currently close to returning to fitness.
"Tyrell is the furthest [along] at the moment," said Van Nistelrooy. "He's been part of team training for a couple of weeks now, fully in team training with no restrictions. It's good for him to plan game minutes, maybe in the under-21s, we have to see.
"Harry is still inside working on his rehab, Luke also does pitch work like he did today and he's progressing there to do hopefully partial team training soon."
When will Mainoo be available for Man United?
Man United have been without the services of Kobbie Mainoo since the start of October due to a muscular problem, and the England international will again be unavailable for selection against PAOK.
However, the 19-year-old recently said that he would "be right back" in a post on social media, suggesting that he will make his return in the not too distant future.
Toby Collyer is also still currently on the sidelines for Man United, but Mason Mount, Christian Eriksen and Antony are all back in training after recovering from recent problems.
The Red Devils will play their fourth European match of the season against PAOK on Thursday evening before welcoming Leicester City to Old Trafford in the Premier League on Sunday afternoon.