Jo-Wilfried Tsonga does not feel Andy Murray is the player he was and claims locker-room rivals are less fearful about facing the Scot.
Their fourth-round clash at the US Open on Monday should provide a real measure of where Murray's form is after an up-and-down first three rounds.
The Scot has not faced anyone inside the top 70, yet has already dropped sets to Robin Haase and Andrey Kuznetsov, either side of a good performance against Matthias Bachinger in round two.
The good news for Murray is he will surely be back on Arthur Ashe, a court he loves, for the Tsonga match and away from his nemesis, Louis Armstrong Stadium.
Should Murray win, it would be his first victory over a top-10 player since lifting the Wimbledon title last year.
Tsonga said: "The locker room is maybe a bit less afraid of Andy because he's losing a few more matches than in the past. But I don't know any player who once on court is going to be super confident against Andy.
"He's different than in the past maybe because I feel he's not serving as strong as he used to, nor maybe hitting as strong as he used to.
"And during matches he's showing more when he seems in pain with his back or hip region, I'm not sure. You can see it on some moves, too."
Murray declared himself in the best shape since before his back surgery almost a year ago when he arrived in New York, and maintained that is the case despite his cramp issues in round one.
He is no longer in pain from his back but has struggled to maintain his intensity through matches and has developed a bad habit of allowing leads to slip away.
He was pegged back by Kuznetsov after looking in complete control at a set and a break up, and went on to drop the third set, but Murray was happy with the way he handled the lows.
"Each time I had a slip, I did a decent job of getting myself back into the sets, getting a break straight away," Murray said.
"Even when I got broken at the end of the match, I broke the next game. When I was down 4-1 in the third set, I got myself back into the set.
"That's really what you need to do. You need to give yourself opportunities in every set and in matches. Then it will start to become natural again."
Murray was unable to turn things back his way the last time he met Tsonga, in Toronto earlier this month, when from 3-0 up in the deciding set he allowed the match to slip away.
It was Murray's first loss to Tsonga in a competitive match since the Australian Open in 2008 and he retains a dominant 9-2 lead in their head to head.
"I played a good match," said eighth seed Murray, looking back to the Toronto match.
"I was up a break in the third set and didn't manage to close it out. So obviously if I get myself in that position again, hopefully I'll do a better job of that. But I don't need to change too much.
"It will be a tough match. We've played each other a lot of times. He's obviously playing well right now. He had a great week in Canada. He's played some good tennis so far here.
"I've had a lot of close matches with him but I've won a lot against him, as well. I would say (my game) matches up well."
Tsonga had been having a poor season until Toronto, where he beat Novak Djokovic, Murray, Grigor Dimitrov and Roger Federer back to back to lift the second Masters title of his career and climb back into the top 10.
The 29-year-old is not reading too much into his win over Murray and admits the best-of-five-set format in slams does not suit him as well as best of three.
"Andy is someone I know very well, against whom I don't have a good record," said Tsonga. "But I'm feeling good. I expect to play a good match. Playing three sets, it's always more physical. I like when it's in three sets.
"(Toronto) is positive because it means that I'm able to play well against him. I hope I will do that again.
"One shouldn't overestimate this win, he still leads our head to head and now he'll be aware of the danger and maybe it plays against me.
"A bit as with Djokovic, he's really tough for me because he returns very well."