Radmilo Armenulic made his name in tennis a long time ago as a longtime player and coach in his native Serbia which was then part of the much larger Yugoslavia.
Armenulic spent many years at the Yugoslav Davis Cup captain, 17 in total, making him the longest tenured Davis Cup captain of the now defunct country, as well as those countries and that were formed when the former one disbanded. He also worked as a tennis coach most notably training a young Goran Ivanisevic. Despite Djokovic's loss to Medvedev, Armenulic still believes Djokovic is on course to make history. He said:
"I
think he’s got two or three years left at the highest level and he has
every chance of winning another three or four slams, which would be
enough to make his tally unbeatable. His
age will at some point undoubtedly become a factor and the younger
contenders are at an advantage because they can still improve whereas
all he can do is work hard to stay on his current level."
It's a view many share with Armenulic as it's hard to see how Djokovic's tally will remain at 20 forever. The Serbian was practically dominant this year and despite his age, it's hard to see how his level could drop off significantly next year. Asked what contributed to his defeat, Armenulic said:
"Djokovic
was under tremendous pressure from the Serbian audience and exhausted
after the semi-final win over Alexander Zverev. He looked flat and
didn’t move well on the court. Fans
and media in Serbia practically demanded victory and it was clear from
the start that he came into the match with so much weight on his
shoulders. He couldn’t get it out of his head and it cost him the title."
The next opportunity for Djokovic will come in January at the Australian Open where the Serbian has been dominant for years.