Frenchman Claude LeRoy has criticised the new timing of the Africa Cup of Nations, saying that top players arrive exhausted after a long European season.
The finals are being played in June-July for the first time in their history in Egypt, having been played in January-February in recent times.
"The top players are burnt," the 71-year-old, who has coached at a record nine Nations Cups, told BBC Sport Africa.
"Mohamed Salah - it was very difficult for him. Sadio Mane - yes, he has scored some goals but he has not influenced.
"He's a fantastic player, a huge talent, but you can see he is not completely ready for this type of competition on a physical or mental level."
Both Egypt's Salah and Senegal's Mane have had two largely uninterrupted years of football.
The Liverpool stars played a full season in 2017-18 as their Premier League side reached the Champions League final, before heading to the 2018 World Cup shortly after and then playing another extended season as Liverpool reached and won the Champions League.
Three weeks later, the Nations Cup kicked off as Salah's Egypt beat Zimbabwe in the opening game.
While Salah and Mane may have lit up both English and European football this season, they have shone in fits and bursts in Egypt.
The Egyptian looked leggy in the group stages and struggled to influence games despite scoring twice prior to their shock Round of 16 exit, while Mane has scored three goals but was largely anonymous as the Senegalese reached their first final since 2002 on Sunday.
With the expansion from 16 to 24 teams, players now have to play an extra match - seven rather than six - if they contest the final.
"For me, the best period was in January-February when they were playing a lot of games for their clubs in England, Germany, Spain, Italy, France or in other countries," added LeRoy, who is currently in charge of Togo.
"Sure they were missing some games but maybe that's the contribution Europe can sometimes give to Africa."
One of the main reasons the Confederation of African Football gave for moving the tournament, in 2017, from earlier in the year was the regular club-v-country rows that regularly broke out ahead of the finals.
At the last Nations Cup, Cameroon won the tournament despite missing around half a dozen players who excused themselves for reasons ranging from differences of opinion with the federation to not wanting to lose their club place.
"80% of the players at this Nations Cup play outside of Africa - and they are not just here but also very focused," Caf secretary general Mouad Hajji told reporters on 5 July.
"Because before the players were always thinking about their return to their clubs and whether they would keep their place, so now we see players far more liberated and who express themselves more."
LeRoy is also worried at how the move to June-July will affect players given the different weather conditions across the continent.
While the Egyptian heat has been intense for many of the games, with Uganda international Emmanuel Okwi saying footballers should not have to play in such conditions, there are also concerns about how matches might be affected by playing in the equatorial belt in 2021.
"We were perfect for most of the countries in January-February and suddenly we now play in June-July where it is 40 degrees," said LeRoy.
"The physical level for the players is very bad and when they finish this competition, some players will have to immediately return to pre-season with their training. I'm afraid about next season for some of these players."
The next tournament is scheduled to be played in Cameroon, where it is expected to be wetter and more humid - so presenting different problems for both players and organisers.
"Cameroon will have the rainy season, so what will happen if a game has to be suspended because of rain? This can create a lot problems."
However, LeRoy, who won the 1988 Nations Cup with the Indomitable Lions, has welcomed the expansion to 24 teams, saying it has given the opportunity to teams like Madasgascar - the fairytale story of this Nations Cup - to shine on African football's biggest stage.
He also praised the "fantastic" hosting in Egypt, where organisers had just five months to prepare for the largest Nations Cup in history.
"In terms of organisation, quality of pitch, quality of training field, quality of hotel for the teams - at this level, it's fantastic," ventured the former coach of Senegal, Congo, DR Congo, Ghana and Senegal.