Liverpool manager Jurgen Klopp believes Neymar's world record move to Paris Saint-Germain should serve as a warning to Barcelona that Lionel Messi's release clause can also be triggered in the future.
The Brazilian moved to the Ligue 1 side after completing a €222m (£198m, $263.7m) move earlier in the month in a deal which smashed the previous world record fee Manchester United had paid Juventus for Paul Pogba after his £89.3m ($118.1m) move to Old Trafford last summer.
The signing sent shockwaves across the footballing world with many, like Klopp, wondering how the Qatari-backed club were able to secure such a deal without offloading any players to comply with Uefa's Financial Fair Play rules.
With PSG now reportedly after Monaco's Kylian Mbappe, Klopp has warned the top clubs that the highly-inflated release clauses of many players will be triggered much more often.
"It's pretty simple. Until now it was simply seen as impossible," Klopp told DAZN, as quoted on FourFourTwo. "Then there is the list, with the release-clauses for Barcelona. Leo Messi, €300m."
"In a period of just a month that suddenly sounds possible too. That used to be an outrageous amount. They just set that amount randomly. I mean who would pay €300m. And now it simply happened."
The German then suggested a rule that would limit the amount a club could spend on a player, stating that no manager would demand such an exuberant fee if not for the higher-ups.
"I don't even know if this is right," Klopp added. "No coach would demand such a thing. That's been decided on other levels and now he is a PSG player, obviously. A simple solution would be a rule. Where we want to go and where this should stop."
"The biggest clubs can decide on that, where they would want to set a limit. €150m or €550m or whatever and then no one would complain anymore. This is a topic now since it happened for the first time."