Jurgen Klopp said it was "a catastrophe" for Liverpool to learn next year's Africa Cup of Nations has been moved to start in January.
The tournament in Cameroon had been due to be played in June and July, during the off-season for many European leagues, and Liverpool had been planning accordingly.
However, concerns over weather conditions at that time of year meant it was decided to move it on the calendar, which also means there will be no clash with an expanded Club World Cup in China.
While the Africa Cup of Nations will go ahead in cooler temperatures, there was no disguising Klopp's heated response to the decision.
"[It's] for us a catastrophe in that moment losing three players," Klopp said.
"We have absolutely no power. If we say we don't let him go, the player is suspended. How is that possible that the company who pays the player cannot decide if the player has to stay or not?"
BEIN EXCLUSIVE: KLOPP AND WENGER ON MANAGEMENT
He could lose the likes of Mohamed Salah, Sadio Mane and Naby Keita for weeks on end, putting a major dent in plans for what could be a season where Liverpool, this term's runaway leaders, are defending the Premier League title.
Klopp admitted his transfer plans could also be affected by the Confederation of African Football's (CAF) decision, saying it was a move that did African players no favours.
The tournament will run from January 9 to February 6, CAF said.
LIVERPOOL LAND FIVE IN 2019 UCL TEAM OF THE YEAR
"Do we really want to open this book now?" Klopp asked, when the subject was raised in a news conference on Friday.
"I couldn't respect the African Cup of Nations more than I do. I like the competition and I've watched it a lot in the past. It's an obvious problem that you play a tournament in the middle of the season.
"I get it that it makes more sense for Africa to play it maybe in our winter, their winter as well, so when the weather is better for them.
"A couple of things which are not OK – one thing is, FIFA plans a tournament [the Club World Cup] in the summer of 2021, a week later or so than the actual Africa Cup of Nations will have started [under the previous plans], I think, or maybe two weeks later, another tournament for a lot of world-class players.
"I mentioned that in the past. I'm not sure if that was part of the decision, when they thought it makes no sense to play it after that tournament so let's play it again in the winter, I don't know.
"Or was the weather the real [reason]? It means another tournament. It's too many tournaments, still.
"The other thing is, it doesn't help African players. We will not sell Sadio, Mo or Naby now because they have a tournament in January or February, but if we have to make a decision about bringing in a player, it's a massive one.
"These decisions are made without asking players, without asking managers, without asking anybody, it's just a decision. FIFA doesn't look like being involved. They're happy having their 24-team [Club] World Cup, offering a lot of money for all the clubs involved. We forget these tournaments are played by players - they don't have a break."
