Following confirmation from the Italian government that clubs were allowed to resume training activities, Ronaldo was scheduled to return to Turin from his home in Madeira on Sunday evening.
However, the 35-year-old has been unable to leave the country after his private plane was prevented from leaving Madrid due to coronavirus-enforced travel restrictions, according to the Daily Mail.
It has been claimed that Ronaldo's plane attempted to take off on three occasions before the planned flight was abandoned, leaving the five-time Ballon d'Or winner with an extended wait to rejoin his teammates.
Sporting events in Italy had initially been suspended until 18 May, but the time period was brought forward following a relaxation of restrictions across numerous regions in the country.