Manchester United will reportedly not know the extent of Robin van Persie's injury blow until Friday.
The Dutchman was stretchered off the pitch at Old Trafford after netting a hat-trick in United's victory over Olympiacos on Wednesday night.
After witnessing his side secure a place in the quarter-finals of the Champions League, manager David Moyes told reporters that Van Persie's injury behind the knee did not look "that bad".
According to Sky Sports News, United will reveal the extent of Van Persie's injury tomorrow during Moyes's press conference ahead of their trip to West Ham United.
United will also discover tomorrow whether they will face Chelsea, Real Madrid, Barcelona, Paris Saint-Germain, Atletico Madrid, Bayern Munich or Borussia Dortmund in the final eight of the Champions League.