The pair were due back later than most of the United squad because they were on international duty in June, but they did not report back, according to Manchester Evening News.
The defenders did not come back as they are not part of Erik ten Hag's plans for the future. They are not expected to be included in the squad as the Red Devils head off for their pre-season tour of the United States.
Bailly and Telles have a year left on their contracts at Old Trafford and United have the option to extend their deals by a further 12 months. The club will either sell the pair this summer or else let their contracts expire at the end of the season.
Bailly, 29, spent last season on loan at Marseille and played 17 times in Ligue 1 while 30-year-old Telles enjoyed a strong campaign at Sevilla, where he made 38 appearances in all competitions. Ten Hag's team will take on Lyon in Edinburgh on July 19 before their US tour kicks off with a game against Arsenal.
Source: goal