The 24-year-old German has faced criticism throughout his time at Anfield, having been snapped up from Mainz in the summer of 2016.
He was acquired to provide competition for Simon Mignolet, but was soon thrown in at the deep end by Jurgen Klopp as Liverpool struggled for consistency between the sticks.
That has remained the case in 2017-18, but Karius is now established as the Reds’ first-choice and is being backed by a club legend to go from strength to strength.
Grobbelaar told Off The Ball amid talk of Klopp potentially dipping back into the market for a new keeper in the next transfer window: “You have [Virgil] Van Dijk holding the fort at the back and you have Karius in goal.
“Karius will become the best value for money goalkeeper in the Premier League in the years to come."
“He cost £4m from Mainz, he is going to be immense, because I tell you what, he has come on leaps and bounds since Van Dijk has come in at the back.”
Karius is expected to form the last line of defence for Liverpool on Saturday when they take on Real Madrid in the Champions League final.
He will be hoping to keep a clean sheet, but a contest in Kiev is set to see two of Europe’s most attack-minded sides go head-to-head.
Grobbelaar, who helped the Reds to European Cup glory in 1984, added: “I think we’ve got the quickest counterattacking forwards in the Premier League with [Mohamed] Salah, [Roberto] Firmino and [Sadio] Mane.
“I predict that there will be goals, and we will score, no doubt about it. It’s about how much we concede, but I’m going to go with 3-1 to Liverpool.”
