The Reds shot-stopper joined the Bundesliga outfit last month on a season-long loan deal, having endured a two-year stint on loan with Besiktas in Turkey prior to leaving for Germany.
Karius is yet to make his debut for his new side and is hoping to get his career back on track with his return to Germany, having already been on the books at Mainz before his arrival on Merseyside in the summer of 2016.
The 27-year-old, who is still trying to rebuild his reputation after his horror showing for the Reds in the 2018 Champions League final defeat to Real Madrid, insists Klopp has always been fair and honest with him throughout his stay at Anfield.
Karius revealed the Reds boss backed his move to Union Berlin and encouraged him to get back to his best between the sticks at the Bundesliga club.
“He was always fair and honest”, Karius told the media when presented and asked about working with Klopp.
“He always tells you what the situation is like.
“We always had a good relationship and never had a problem.
“His success speaks for itself.
“He is currently one of the best coaches in the world.”
Asked about what Klopp feels about his move to Union Berlin, Karius said: “He said it is a good step and I have the chance to distinguish myself here and that I can show everyone that I’m a really good goalkeeper. “
Union Berlin have picked up four points from their opening three Bundesliga games so far and are in action this weekend away at Schalke.
