Any mention of Aston Villa, or any glimpse of them ahead on the fixture list, is bound to send a shudder down Jurgen Klopp's spine.
That 7-2 thrashing Liverpool suffered at Villa Park back in October was one the worst, if not the worst, result Klopp has experienced in his distinguished career.
Just four games into their Premier League defence, the capitulation didn't exactly augur well when it came to back-to-back titles.
Fabinho (left) and Georginio Wijnaldum (right) played alongside Keita in a midfield three against the Spanish champions - but the plan backfired for Klopp
And so it has proved.