United won the first-leg of their Europa League semifinal 6-2, having at one stage been 2-1 behind.
Afterwards, Rizzi-gol declared: "They gave up everything, now there is nothing more to do.
"It's hard for us to say believe it if they don't believe it. If they had done so, there would have been 3000 people (at training) to push them, there is no doubt after what we have seen yesterday.
"It takes personality, even on the penalty, scandalous, no one protested. Others would have forced him to go to the VAR by surrounding him!"