Gillis began by representing some former teammates, and over the years, his list of clients grew to include stars Pavel Bure, Tony Amonte, Markus Naslund, Mike Richter, Valeri Bure, Bobby Holik, Pat Verbeek, Ulf Dahlen, Peter Zezel and Marcus Ragnarsson. What makes Gillis' success as an agent even more remarkable is the fact that during his own playing days, he was represented by the notoriously corrupt Alan Eagleson, who later went to jail for defrauding many of his clients, including Gillis. After Gillis' stopped playing, he was eligible to receive disability insurance payments from the NHL. Although Eagleson had no right to do so, he convinced Gillis to pay him 15 percent of his disability money. He lied to Gillis in claiming that he had negotiated the a special disability deal, getting more money than Gillis would have otherwise received. Over 10 years later, in 1997, Gillis successfully sued Eagleson for $570,000, most of which went to cover his own legal costs for pursuing the lawsuit.