The Ivorian has missed the last eight matches after picking up a blow in Man United’s 1-0 defeat away at Stamford Bridge to Premier League champions Chelsea on November 5.
Bailly’s absence was acknowledged, but the extent of his injury was not known or prominently discussed. The Sun suggested this week that the 22-year-old could be out of action until the end of January.
Having missed eight games, including vital clashes against Arsenal and Manchester City, Bailly could miss almost 20 games if he is forced to have an operation.
Mourinho told reporters after Wednesday night’s 1-0 victory against AFC Bournemouth in the Premier League that Bailly has indeed suffered a “serious” injury and accepted that if treatment does not work, he will require surgery.
“I think it’s serious,” he said. “[How long?] I don’t know. We are trying a conservative treatment, but if that’s not working he’ll probably have surgery.”
It’s a huge blow to both Bailly and United. Mourinho has shown with his starting line-ups in important games that Bailly is his first-choice centre-back.
Phil Jones and he formed a promising partnership at the start of this season until both suffered a couple of knocks as the fixture list began to pile up in October and November.
Jones made his first appearance in over a month on Wednesday, his last game having been that Chelsea loss. The Englishman aggravated a muscle injury while on international duty with his country, coming off after less than half an hour for the Three Lions in a friendly against Germany.