Edinson Cavani will not make his Manchester United debut in their next Premier League game at Newcastle due to having to quarantine, but will be available to face former side Paris Saint-Germain in the Champions League.
United's new number seven, who arrived on Deadline Day on a free transfer, will still be self-isolating when the club travel to Newcastle on October 17.
The striker could feature three days later against PSG in Paris, although the 33-year-old may not be deemed fit in time to face his old club as he is unable to train with his new team-mates until the quarantine is over.
Having been a free agent, Cavani has not been part of an elite sport 'bubble' meaning he is not exempt from the 14-day quarantine which people arriving from France must adhere to under current coronavirus guidelines.
- Transfer Talk: Man Utd became 'deluded' over Sancho fee
- 'Under-pressure Ole must win trophies after signings'
- All the Deadline Day deals
Cavani was one of four Deadline Day signings for United as the club also completed deals for Alex Telles, Facundo Pellistri and Amad Diallo.
He signed a one-year contract with the option of a further 12 months, and will provide stiff competition for United's current first-choice striker Anthony Martial.
"Clearly Edinson Cavani has the work-ethic, the hunger to be a success at Manchester United," reported Sky Sports News' James Cooper. "He's been impressed by the project he's been offered by Ole Gunnar Solskjaer, and in return Solskjaer has been impressed by Cavani.
"Solskjaer has said he will score goals. He won't sit on the bench and he is someone who will deliver something they haven't got with their other striking options.
"United are confident Cavani's signing could have a similar effect to that of Zlatan Ibrahimovic, who arrived in the summer of 2016 at the age of 34.
"They believe Cavani's experience and credentials would encourage the development of Mason Greenwood while also providing support for Marcus Rashford and Anthony Martial, as well as adding a different attacking component for Solskjaer."
Cavani became PSG's all-time record goalscorer with 200 goals in 301 games across all competitions, and the Uruguayan could now face them twice with United before Christmas in Group H.
'Cavani can't have been part of United's plan'
Sky Sports reporter Dharmesh Sheth said: "At the start of the window, would it ever have been part of United's plan that on deadline day they would be bringing in a 33-year-old striker [as a free agent]?
"I can't imagine it was, when they were talking about Sancho, Alex Telles and the potential of signing a centre-half. It can't have come up. This is a 33-year-old who hasn't played football for seven months.
"I can't imagine that it could've been in the plan."
Speaking on the Transfer Talk podcast, Raphael Honigstein added: "It's a really interesting signing as it doesn't seem to fit into the reboot we've been hearing about at United. At the same time, by all accounts, Cavani is an unbelievably professional player with his presence and his dedication to his craft.
"This will have a positive effect on the young players around him, especially in attack, and of course he is somebody who will score you goals if you serve him properly.
"On a one-year deal, I feel it is the stop-gap solution that can help you but it doesn't really do anything in terms of growing the team or the club to be back where they want to be. He's the opposite of a Timo Werner. Werner is going to be at Chelsea for the next five or six years as your No 1 striker, or maybe your second striker.
"Even if Cavani does incredibly well, United are going to still have to go back into the market soon to find the next Cavani. It's not a criticism but it's the one factor that United have to be aware of."
Press and Heath shirts outsell Utd men's players
Christen Press and Tobin Heath outsold any of Manchester United's male players in terms of shirt sales in the first three days following their arrival.
The US Women duo were two of many high-profile WSL signings this summer, and their names were clearly in demand from United supporters across the globe.
Analysis: The deal that didn't happen - what now for Sancho?
Sky Sports News' Kaveh Solhekol:
"This window has been dominated by the Jadon Sancho saga. It's been suggested United will return for him next summer, but I would be surprised if Jadon Sancho ever played for Manchester United. If United don't sign Sancho now, they may never sign him.
"If you speak to people close to Jadon Sancho, after what he's been through this summer with regards to Manchester United, would he want to go through all of this again? There will be lots of other clubs trying to sign him next summer."