Liverpool had included an unusual transfer clause into the deal that saw Philippe Coutinho leave for Barcelona in 2018.
However, it has not gone to plan for the Brazil international – who failed to stamp his ability on the squad.
And this season he was loaned out to Bayern Munich to help boost his confidence.
There had been rumours that a move back to Anfield could be on the cards.
But Liverpool do not have a buyback clause and would have to negotiate a price with the Catalan club.
However, Anfield chiefs had the foresight to include one term that means that the Spanish giants would have to pay a premium of £89m (€100m) for any Reds player they wished to sign before 2020.
That means it effectively ended any chance Barca had of signing the likes of Mohamed Salah or Sadio Mane.
And that became a masterstroke after the Champions League encounter between the two.
Barcelona would no doubt like to have a chance to sign the likes of Salah, Mane or even Roberto Firmino.
But the clause automatically would whack the price up further than what Barca would like to have paid.
This article was most recently revised and updated 2 years ago