The Reds got a dose of their own drugs as Atletico harassed and hassled throughout, limiting them to just 2 clear probabilities and no shots on target.
Those opportunities fell to Mohamed salah, who headed wide, and Jordan Henderson, whose hooked shot simply missed Jan Oblak’s far post.
Klopp replaced Sadio Mane and salah with Divock Origi and Alex Oxlade-Chamberlain however neither created an impact.
Two-time finalists Atletico, who are on a poor run of form, remained to a fourth-minute lead given to them by Saul.
The Spanish midfielder turned sharply to fire home after a corner came off the boot of Fabinho.
The return leg is on Wed, 11 March.