And the likes of Leigh Halfpenny and Keith Earls were relatively unknown when they returned to the Rainbow Nation 12 years later.
The Wallabies have also turned to untested stars with wing-cum-full-back Andrew Walker converting from rugby league to start all three Tests against the Lions in 2001.
And Gregan, who was part of that victorious Test series, reckons the Wallabies may have pinched another star in the making from the 13-man code in Israel Folau.
The 23-year-old has switched to union, and Super Rugby's NSW Waratahs , after becoming the youngest player to represent Australia and Queensland in the State of Origin.
"Israel is a household name in Australia because of his league background," said Gregan.
"He is just an incredible athlete. It might be a bridge too far to make the Wallaby team, to understand the game in time for the Lions series, but you just never know.
"I'd have him on the wing, maybe 13, but that is a big transition, to learn the defensive lines and running lines in general.
"He is used to being on the end of an attacking line, so wing probably, but you also have Digby and James O'Connor. That's a good problem."
Another player to keep a close eye on in the upcoming Super Rugby season, which kicks off in February, is ACT Brumbies' Christian Lealiifano.
The fly-half was in red-hot form last season before suffering serious injury and Gregan reckons he will provide real competition to the ever controversial Quade Cooper.
"He hasn't played for the Wallabies yet but Christian Lealiifano of the Brumbies was the premier 10 last year until he broke and dislocated his ankle so there are other options, added Gregan
"Lealiifano has everything: magic hands, pace, power, agility and a ridiculous siege-gun boot."