Mata admits it angers him when people criticise the manner of their success.
"After the Champions League final it hurt to hear people saying the football we played had no merit," he told So Foot.
"Every way of playing has merit. If you tell me Chelsea's football is not as good to watch as Barcelona's, I can understand. I can accept we were not the most talented either. However we were the most competitive.
"So, like it or not we did not steal the Champions League.
"I don't understand why people want to constantly under-estimate what we achieved last season. Knocking out Pep Guardiola's Barcelona is anything but simple - but we showed that it's possible."