According to the Daily Mail, the 23-year-old is currently in France after being given an initial 10 days' leave by QPR for treatment.
Diakite featured in Rangers' first two Premier League games of the season and was given permission to go to France following their 1-1 draw with Norwich on August 25.
QPR's club doctor has regularly made trips to France to check on the Mali international, who is said to be on a special fitness regime in the European country.
It has been reported that Diakite will be given as much time as he needs to recover by QPR. The reason for the former Nancy midfielder's condition is not yet clear.