Jose Mourinho said Arjen Robben is unfairly targeted by opponents because of his speed and called for technology to help referees stop divers.
And, while Mourinho said Robben can try to earn an advantage through going down, he also claimed the winger is "punished with fouls" by other players.
He told Yahoo! Eurosport: "My opinion on Robben? He was my player and I know better than many what a fantastic player he is. I also know that because of his speed and because of his creativity he is punished a lot with fouls by opponents who cannot stop him. I also know that sometimes he tries to get an advantage and he tries to win a free kick or he tries to get a penalty.
"I think it's important for the players to help the referees and to help the referees is to be honest on the pitch and to help the referee is to be pure and to try to win the right way. But the reality is that not every player behaves that way and referees have a difficult job.
In situations where a player is suspected of simulation, the Chelsea boss would back a fourth official assisting the referee by viewing a television replay of the incident.
Mourinho added: "If you have technology you can have a chance to have a fourth official watching on the video or screen situation. So I think the referee should also be happy to have the chance in case of doubt, the chance to clear every doubt and the chance to make the right decision because when one country feels that one bad decision influences its future in the competition I think it's hard and I think it's important for coaches, for players but also referees.
"I think technology is something the referees would welcome."