Speaking at the Soccerex football business conference, England coach Roy Hodgson said international breaks are seen by clubs as a chance to give players a holiday.
"I would like to see the international break being taken seriously," he said. "I'd still like to see it as a time when players go to play for their international teams. These breaks are being seen as the 10-day break that players don't always get during the season."
"It doesn't matter what way you look at it. Club managers are always in disagreement with international football, particularly in friendly situations.
"Friendly games, for the last decade, have been played the Wednesday before the season starts," said Ferguson. "You tell me the sense of that.
"I've got no issues with competitive matches.
"But you can't tell me that should apply itself for friendly games."
"I think that in England you need to have a break in December for the national team because we play a lot of games," said Mancini.
"The moment that they decide to give players one week off in December it will be good for the teams and national team."
"I don't know what Roy is saying there," he said. "International friendlies are quite often meaningless games.
"Roy's been a club manager and I'm sure when there was a break he was only too pleased to have a day or two's rest to give the players a rest or take them away to train.
"Roy's entitled to his opinion, but most clubs take the chance to get away and have a change of environment."