Prior to the suspension of the tennis season due to the coronavirus pandemic, Djokovic was in the midst of playing some of the best tennis in his career.
The Serbian had won 21 singles matches in a row, last tasting defeat to Roger Federer at the ATP Finals in November.
He started the 2020 season by winning the inaugural ATP Cup and then the Australian Open for the eighth time, which allowed him to regain the world No 1 ranking from Rafael Nadal.
In February, he won his fifth Dubai Championships title and was primed for a strong run in Indian Wells and Miami before the decision was made to cancel the tournaments on health and safety grounds.
Djokovic’s longest run without defeat came in 2011 when he won 43 matches in a row before Federer beat him at the French Open.
And while Martin concedes Federer is the better player to watch, he feels Djokovic’s winning mentality puts him above his rivals.
“Roger is the most aesthetically pleasing I have ever seen,” Martin told Tennis365.
“For me though, if Novak is right, if Novak is confident and comfortable with his physical status and is really focused, I’ve never seen anybody more unbeatable.
“This guy has played the game better than anyone else ever has, in my opinion.
“His athleticism is from another world. His return of serve is way better than any other return of serve ever and I mean way better.
“Nobody has gotten so many balls back and neutralised so many good serves.
“Having worked with him, when he is focused he has that I’m going through a brick wall mentality.
“Now he is not always focused, but when he is and we have seen this for long stretches, he doesn’t have to play great. He is that much of a fighter and thrives on it.”
