Peter Fleming says Roger Federer would need to restructure his entire clay court game if he is to beat Rafael Nadal at the French Open.
The Sky Sports expert was speaking after watching the Swiss superstar get completely outplayed by his long-time rival in a Rome Masters final that lasted just 68 minutes.
Nadal strolled to a 6-3, 6-1 victory and with the second Grand Slam event of the year barely a week away, Fleming feels Federer would need to make huge changes if he is to compete with the king of clay.
He said: "Check out these stats. Rafa had eight unforced errors to Roger's 32. That's a difference of 24. That's a whole set right there where Roger over-hit or wasn't sharp.
"We have to remember this is only his second tournament back after a seven-week lay-off and he wasn't sharp enough to play Rafa today.
"Should they play in Roland Garros it's going to be a lot more competitive I would have thought, but he's still got to re-think his tactics against this guy.
"He needs to change his whole game really. One of his great weapons prior to Rafa was his ability to hit sliced back-hands effectively.
"He could use that shot to take other players out of their rhythm and open up the court, but against Rafa he's just not allowed to hit that shot. Every time he hits a sliced backhand to Rafa he loses the point because Rafa attacks it or gains the upper hand in the rally.
"As of now, off the backhand he just doesn't know what to do."
After missing the early part of the season through injury, Nadal has won six of the eight tournaments he has competed in and Fleming believes he could be on course to match the record of 11 victories that he established in 2005.
And he says the rest of the field will be quaking in their boots at Roloand Garros next week.
"No question about it, Rafa, even at half-form, is the best clay-court player in the world," Fleming added.
"Roger would have to say that his greatest hope is that somebody else takes Rafa out in the semi-finals and he sneaks through in the other half and plays another player.
"He would feel he'd have a great chance against anyone else but Rafa. This match-up just doesn't work for Roger.
"He's the favourite to win at Roland Garros and let's just say that he does go on and win that, then he's be the favourite to go on and win at Wimbledon.
"Who's to say that he can't get to 11 tournament wins? It's largely a matter of health."