Manchester United midfielder Kobbie Mainoo did not feature in a behind-closed-doors friendly against Barnsley after having a slight setback in his recovery from an ankle injury.
The midfielder has been training with the first team again for the first time since pre-season, having been pictured with the rest of the squad in the build-up to the Champions League match versus Galatasaray last week, but his return date has now been delayed.
Raphael Varane missed the 2-1 win over Brentford last weekend due to a minor knock. The Frenchman is expected to be back available after the international break.
Lisandro Martinez underwent surgery on a broken metatarsal earlier this month. The defender has been carrying the issue since the back end of last season, and he had been taking painkillers to get through matches.
However, it was decided that the defender needed to get the injury sorted once and for all. He is expected to be sidelined for 3 months, with his return pencilled in for early in the New Year.
Updates on 5 other United players
Sergio Reguilon should be ready to face Sheffield United a week on Saturday after recovering from a hamstring strain.
His fellow left-back Tyrell Malacia has not been seen in action since May, with the 24-year-old said to be trying to overcome a chronic knee injury.
There is some hope that the Dutchman will be back in contention within the next few weeks but, as he missed pre-season, it will take time for him to get up to match fitness.
Luke Shaw is expected to be out for a while with a muscular injury, while Aaron Wan-Bissaka may not be available until mid to late November due to a hamstring problem. Amad Diallo is still in rehab with a knee injury.