The ATP banned the elder Tomic from all events following his assault on Drouet outside a Madrid hotel on May 4.
The 20-year-old Tomic has a promising career, but it's been sprinkled with controversy.
In November, he was fined and put on a 12-month good-behavior bond after twice being stopped by police for driving offenses near his Gold Coast home.
In late October, police were called to a high-rise apartment building in the Australian resort of Surfers Paradise after residents saw two men, one of them naked, wrestling and fighting in a hot tub on the balcony. One of the men was later identified as Tomic.