The Serbian midfielder is currently on loan at Porto, following two successful seasons at Bundesliga side Hertha Berlin.
Grujic was expected to be given a chance upon his return to Merseyside in the summer.
However, the Reds reject admits he was left confused by Klopp's conversations and then subsequent snub of his services.
“In every conversation, be it Klopp or one of the directors, they always remind me that I am a player of great potential,” Grujic told Serbian outlet Kurir.
“But when I get into the system I don’t get a chance. It confuses me a little.
“I told the people from Liverpool that I wanted to play. Hertha, where I spent two beautiful years, was an option, as were some other Bundesliga sides, [but] Porto happened.
"They sold Danilo to PSG and needed a player with my characteristics.
“They wanted me and it was all done in a few hours.
"For me, Porto is a great option, a team fighting for the title and playing in the Champions League, a new experience.”
Liverpool are suffering a massive injury problem at present, with Klopp depleted in defence and midfield.
And with the benefit of hindsight, Grujic admits he would have been a handy member of Klopp's squad throughout the season so far.
“After two years in the Bundesliga, I returned to England more mature,” Grujic added.
“But when Thiago came from Bayern, I estimated that there would not be much space for me.
“I didn’t want to gamble. I see now that there are a lot of injured players at Anfield, it is certain that I would get a chance, but I could not have foreseen that.”