Klopp Liverpool side are currently cursing the best ever primer league run since over 15 years with 10 wins and 3 draws leaving them unbeaten in the league.
“If Liverpool don’t win a trophy this year then they’ve got a decision to make (about Klopp),” former Real Madrid and Wales manager Toshack said.
He added that although things are looking rosy for Klopp at the moment, he will need to prove doubters wrong by getting a trophy.
“Things look really good at the moment, but this is Klopp’s third full season at Liverpool and this is the acid test for him.
“You can be unlucky not to win a trophy, but at the top clubs that’s what matters.
“It’s such a fine dividing line, but when you’re at a club like Liverpool that’s what it’s all about.”
Klopp initially agreed a three-year deal to become Liverpool manager in October 2015.
He signed an extended six-year deal in July 2016, with Liverpool’s American owners saying it would have been “irresponsible” not to offer Klopp a long-term contract.
“Klopp seems a super guy,” Toshack told Press Association Sport.
“He’s open with the players and tells it how it is.
“Maybe he’s too passionate at times, but the dividing line is so thin between first and second.
“You feel City have got the edge with Pep Guardiola because they’ve got trophies behind them.
“That’s a big thing and Liverpool haven’t won any yet.”