The Belgian, 29, now fears for his place in the Red Devils' squad for Russia this summer if he continues to play second fiddle to 24-year-old Loris Karius.
Mignolet insisted: "I will soon be 30, and the World Cup finals are coming around. My current situation clearly can't continue much longer.
"Roberto Martinez, the Belgium coach, watched the Manchester City game and sent me a message of support afterwards. I appreciate it a lot.
"I know he has a lot of faith in me, and I played well in the recent friendly against Japan.
"But it is always important for me to be playing matches.
"I always try to keep calm, and I have come back stronger from similar situations in the past.
"But of course I have to think about my own future. All I can do is focus in training and do my best.
"Klopp then told me what was going to happen for the Manchester City game. Of course I was not happy, although no harsh words were said.
"He told me honestly that Karius is ahead of me in the pecking order. I am absolutely not happy with this, although I always have to respect the coach's decision.
"After all that has gone on this season, I now know where I am - and the situation has become clearer.
"I have captained the side three times this season. I asked for an explanation to the bizarre situation after the Burnley game.
"I had a premonition about what might happen with me - and it turned out to be correct."