The Cottagershave been relegated to the Premier League after suffering a 2-0 defeat at the hands of Burnley.
Speaking after the game, Mitrovic told Sky Sports: "It's a tough time but we failed today, we failed this season and it's hard to find the words after performance this season, it wasn't good enough
"We didn't deserve it. I have played football long enough and it is an honest game, you finish where you deserve to be. We didn't deserve to stay up. Overall we finish where we deserve, we are really sad for the fans and for the people in the club.
"It is tough to find the words. I think we failed tonight, we didn't show the big character, the big mentality, I think we cracked under the pressure a little bit. We were not good enough. We work hard but we miss the quality at both ends so in a league like this you get punished and we got punished today and this season.
"Not just for me, for everyone. It's been a tough season on a personal level and I want to leave it here, that's football, that's life. We keep pushing, we keep going. We have to finish these three games and see what happens next."