The Swans co-captain will become the second-fastest player to reach the 250-game milestone against Geelong on Saturday, behind North Melbourne champion Wayne Schimmelbusch.
As he has done in the past month, Goodes is set to start up forward against the Cats as the Swans prepare for life after Michael O'Loughlin and Barry Hall.
Roos said the versatile star showed with a best-afield display against Richmond that he could succeed in the new role.
"Where he's played his best football has been as a midfielder but if you looked at his game last weekend against Richmond, he had seven shots at goal [as a key forward] and really dominated that position," he said.
"We need a centre half-forward and we need a key forward with Jesse [White] coming in and Mick and Hally going out so that was a really good game.
"He can have an enormous impact over the next two or three years if we continue to play him in that role."
Roos said Goodes's versatility set him apart from many of his talented contemporaries and a successful transition from champion midfielder to star forward would cement his place among the all-time greats.
"He rucked, he played in the midfield; if he was able to go forward over the next two or three years and have a significant impact on the scoreboard in terms of goalkicking, his legacy would grow even further," Roos said.
"Regardless of what happens in the next two or three or four years of his career, he'll go down as one of the best players in the Swans' history."
Sunday's four-goal effort against the Tigers was the latest of several standout games that Goodes has produced this season and Roos said a third Brownlow Medal wasn't beyond him.
"When he plays well, he plays very, very well and he catches the eye of the umpire. Given his history, he'd probably be a little disappointed in his year as a whole but he's played some very, very good games of football," he said.
"He's not quite as consistent as he was in those Brownlow years but he's certainly had some vote-catching games, there's no doubt about it.
"In the last couple of weeks, he's really bounced back to some of his best form and hopefully he can continue the year like that."
