Jurgen Klopp saluted the "incredible performance" of Adrian despite a lack of preparation time as the goalkeeper's shootout heroics won Liverpool the UEFA Super Cup against Chelsea in Istanbul.
The Spaniard denied Tammy Abraham in the shootout with a trailing leg in the 5-4 victory on penalties at Vodafone Park, with the match level at 2-2 after extra time.
A few weeks ago, Adrian was training with semi-professional side UD Pilas in his country's sixth tier to keep in shape following his release by West Ham United.
He was on the verge of joining Real Valladolid before Liverpool made him an offer to deputise for Alisson as Simon Mignolet joined Club Brugge.