Taking an almost simplified view of the task Renshaw has in front of him in 2012, McEwen who took his first Tour de France win in 1999 despite strained relations with Rabobank management, told Cyclingnews, "It will be a matter of really looking after himself instead of looking after somebody else and saving all the energy for a couple of hundred metres later."
Renshaw will have the support of fast men in Theo Bos and fellow Australian Michael Matthews – hopefully passing some of his knowledge on along the way – at Rabobank in the absence of the team's former top sprinter, Oscar Freire.
"I think he's got massive opportunities in front of him really," McEwen, who will race until the Tour of California with GreenEdge before taking a technical director's role with the new team, said. "It's all up to him. He's played the role of a fantastic lead out man the last couple of years for Mark Cavendish and they've both made a huge difference to each other's careers. Now it's time for Mark [Renshaw], he's decided he wants to have a go for himself and find out what he's capable of and now's the time. It's perfect timing to have a go at it.
"If it works, he's a star, if it doesn't he has the fallback position of being one of the best lead-out men in the peloton, so I think he has nothing to lose."
Renshaw proved that he was up to the task in 2011, given the rare opportunity to go for the win, claiming a stage victory and then the overall at the Tour of Qatar and then late in the season, besting Cavendish on stage 5 of the Tour of Britain. While the 29-year-old was arguably the best lead-out man in the peloton, significantly contributing to the strike rate of Cavendish while at Highroad in its various guises, it remains nothing but off-season speculation as to how each will fare with their new teams.
McEwen though is backing Renshaw's talent, knowing he'll be going head-to-head with another former Highroad teammate, Matt Goss who will be GreenEdge's go-to man in the sprint.
"I think he'll go well," McEwen said. "You saw him sprinting at Credit Agricole in  07 [and] 08 before he joined HTC and became more of a lead out man and he made amazing progress there. If you see the way he then developed in the role at HTC and became the best at it, I think he will still make big improvements as a sprinter but he'll have to, and he knows this himself, he'll have to change the way he's thinking in a race."