The Brazil striker suffered the injury in the 2-0 French Cup victory over Strasbourg on January 23, and after consultation with "world-renowned medical experts", the decision has been made for Neymar to receive "conservative treatment", Sky Sports reported.
"Paris Saint-Germain's Brazilian international striker agreed with this protocol. As a result, Neymar Jr. is expected to return to the field within 10 weeks," a club statement said.
"Paris Saint-Germain sends its strongest support and encouragement to Neymar Jr. to overcome this injury, with the courage and determination that the player has always shown."
Neymar has scored five goals already in the Champions League this season, bettered only by Lionel Messi and Robert Lewandowski, with his absence providing a further boost to a United side rejuvenated under caretaker manager Ole Gunnar Solskjaer.
Runaway Ligue 1 leader PSG travels to Manchester in two weeks' time for the first leg of their last-16 tie, before the return leg takes place at Parc des Princes on March 6 – both too soon for Neymar on the current prognosis.