Preparing for his Wimbledon swansong, Hewitt was the last player to win the singles in 2002 before Federer, and to a lesser extent Rafael Nadal, Novak Djokovic and Andy Murray, dominated.
Federer made his Wimbledon debut with Hewitt in doubles when the pair were teenagers in 1999 and the Swiss legend said it had been special enjoying a career-long friendship and rivalry with the former world number one.
"I played him in Wimbledon, 's Hertogenbosch, Halle, played him on grass as well in Davis Cup in Sydney," Federer said.
"It's been always tough against him on this surface. I think for a baseliner, he was the first guy really from the baseline to have such a major impact as well.
"Plus he's a smaller guy. It was dominated by the big servers for a while. Back then, Ivan Lendl, Jim Courier, they had to really volley to have success. They did it very well.
"But Lleyton was really every point from the baseline. For him to win Wimbledon and have the career he had on the grass is quite unbelievable.
"It showed an entire generation how it can be done."
"I practiced here again with him," Federer.
"It just shows why he's so tough. He hits that flat ball, helps his serve, unbelievable slice, good at net, he's fast, low to the ground. He's got so many things going for him.
"I've always enjoyed watching him. Playing against him has been cool at times, not always so much fun.
"A feisty competitor, one of the toughest I always had to play against.
"I wish that he can play a good match, a good tournament, that he can enjoy Wimbledon after for what it is, and I'm sure he will."
Hewitt faces Finnish veteran Jarkko Nieminen in the first round on day one.
Date: 28th June 2015, Source: ABC AU