Cristiano Ronaldo is continuing to miss full training due to his hip injury.
The Manchester United icon was unable to train last Friday due to the ongoing issue and missed the team's 4-1 defeat to local rivals Manchester City at the weekend.
Ronaldo was not at Etihad for the Premier League clash, as he headed home to his native Portugal where he receiving further treatment.
The 37-year-old was back at United's Carrington training ground on Tuesday morning but did not train with the group; he was assessed by United's medical team and undertook a light session, followed by treatment on the affected area from the club's physios.
Ronaldo is desperate to be ready for the team's next game against Tottenham at Old Trafford on Saturday evening - even with interim boss Ralf Rangnick wary of rushing him back.
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The Red Devils could slip to seventh in the Premier League if they lose to Spurs. They're currently fifth, one behind Arsenal in fourth having played three games more.
But it's just six days until United welcome Spanish champions Atletico Madrid to Old Trafford for the second leg of their last 16 Champions League clash. The first leg in Madrid finished 1-1 thanks to a late Anthony Elanga goal.
Even if he's good to go against Spurs, Rangnick and his team are concerned Ronaldo may struggle to recover to face Diego Simeone's side.
Ronaldo, who has 15 goals to his name this term, is believed to have been suffering with a hip problem for the last couple of months.
The five-time Ballon d'Or winner has scored just one Premier League goal since the turn of the calendar year.
He missed the FA Cup clash with Aston Villa and the subsequent league game against the same opponent in January due to his hip complaint.
Speaking after the City defeat, United legend and Ronaldo's former team-mate Roy Keane was not convinced with the veteran forward's diagnosis.
"There seems to be something more with the Ronaldo situation," said Keane. "The manager coming out talking about something about his hip flexor but the man is a machine and is rarely injured.
"But every now and again he comes out with that about his hip flexor, doesn’t add up to me."
When pressed about Ronaldo's injury, Rangnick said: "I have to believe my medical department.
"My doctor came to see me on Friday morning before training and told me Cristiano Ronaldo cannot train because of some problems with his hip flexor and the same was true on Saturday and that's why he couldn't be part of the squad."
Fellow forward Edinson Cavani also missed United's defeat to City with a groin injury, despite training in the days leading up to the game.
"Edi trained well in the last three days but, in the end, he didn't feel quite well enough to be able to play," added Rangnick.
"What does it help if I tell you it's frustrating? It's just a fact if players tell the doctor and the medical department that they are injured and cannot play.
"I have to accept it as a manager... I cannot force a player to play if he thinks he's not available because he has an injury."
Cavani is expected to be fit for Saturday's meeting with Antonio Conte's men.
