Eyebrows were raised when the 19-year-old right-back turned up for his medical last week at Carrington using crutches although he was able to conclude his shock £19m switch from Porto with the minimum of fuss.
Old Trafford insiders are hopeful the teenager will be fit to start pre-season training and are being provided with regular updates during his current rehab.
Dalot is believed to have suffered the injury towards the end of last season but the Red Devils have provisionally pencilled him in for next month's trip to the United States.
United boss Jose Mourinho moved quickly to persuade his former club to part with the academy graduate, who made a total of just five first-team starts at Porto.
There is little indication so far that Dalot will be an automatic starter when the new campaign gets under way, with United wanting to ensure he is fully fit and settled into his new life in Manchester, with members of his family also planning to accompany him during the early months.
United are keeping quiet about the extent of Dalot's knee injury although there seems little concern that the prospect will not be able to quickly show why Mourinho made such an effort to acquire his signature.