The midfielder made a strong impression during United's opening three warm-up fixtures, featuring in the No. 8 role with new arrival Andrey Santos positioned behind him. However, Mount was caught on the foot during the early stages of Saturday's 2-2 draw against Paris Saint-Germain in Gothenburg.
Head coach Michael Carrick opted to withdraw him before half-time as a precaution. Mount was subsequently able to walk without difficulty to the team coach, but he has not returned to training, making his involvement against Leeds unlikely.
His availability for United's final pre-season outing is also uncertain. The club will face AC Milan, managed by former United boss Ruben Amorim, in Wroclaw on Saturday.
There have been more positive developments elsewhere in Carrick's squad. Lisandro Martinez has been involved in training since United began their six-day camp in the Republic of Ireland, having previously suffered an injury during the first half of the World Cup final.
Marcus Rashford and Kobbie Mainoo have likewise trained this week, although it remains to be seen whether Carrick feels either player has completed sufficient preparation to feature against Leeds.
Youri Tielemans has explained why he finally made the move to Manchester United, admitting the opportunity was too significant to turn down despite his gratitude towards Aston Villa.
Matthias Jaissle has given an early glimpse of what to expect from him after opening up on his "emotional" personality on the touchline.
Chelsea have completed the signing of Pep Chavarria from Rayo Vallecano, with the left-back joining on a five-year contract.
Ivory Coast defender Ousmane Diomande has fulfilled his dream of playing in the Premier League after joining Nottingham Forest from Portuguese giants Sporting Lisbon for a reported 34 million pounds.
