The Ivory Coast international underwent knee surgery in the summer after suffering a serious injury in a pre-season friendly with Tottenham.
It was thought Bailly was on course to return sooner than expected with a November date provisional penned for his comeback to full training.
However, it has now emerged United’s medical staff are concerned by the slow progress the 25-year-old is making in his rehabilitation and are not expecting him back until 2020.
Bailly has endured a nightmare run since joining United from Villarreal in 2016 as Jose Mourinho’s first signing at the club.
After making an impressive start to life at Old Trafford, Bailly has failed to stay fit for prolonged periods and has dropped completely out of favour as a result.
United made Harry Maguire the most expensive defender of all-time in the summer and his arrival forced Chris Smalling to join Roma on a season-long loan deal.
Ole Gunnar Solskjaer’s side are keen to offload two centre-backs on permanent deals in the next 12 months and Bailly’s hopes of salvaging a career at the club are slipping away.
Bailly has only started 43 of a possible 121 Premier League matches for United and the Red Devils have a better win raio when he has started (60.5%) compared to when he hasn’t (48.7%).
