Tottenham manager Mauricio Pochettino fears for the "spirit" of the game with the introduction of VAR.
Pochettino made the comments after seeing his side seal a 1-0 victory against Manchester City in the first leg of their Champions League quarter-final tie.
VAR is set to be introduced into the Premier League next season and Pochettino says: “I think there are many things that we need to try and make clear.
“The spirit of football is going to change, we are going to see a different sport. Not the football we grow up watching, for sure."
The Argentine continued: “We need to be clear and set the protocol, so everyone knows or it is going to be a big problem.
“It is going to be a tough summer, we need to be all involved to try to find the best way to work.
“It is going to be important if it is going to check everything, if it is only handball, it is aggression, I don't know.
“Because today there is a lot of action you can check."