The Reds take on the Portuguese giants for a place in the semi-finals on Tuesday night, but three years ago they asked their B team for help by mimicking Tottenham's tactics in a friendly.
Jurgen Klopp's side spent a week in Marbella to prepare for the final, which they ended up winning 2-0 in Madrid.
The trip was used to keep fitness levels up and get used to the heat in Spain prior to the match.
Benfica B were invited to their training camp for a friendly and their manager Renato Paiva has explained how significant their impact was.
They were asked to analyse and mirror Spurs' approach in every way possible and they were chosen because of similarities in style.
Paiva told Portuguese outlet A Bola, translated by Tiago Estevao, about their assignment.
"We recreated two of their offensive and two of their defensive moments, as well as the set-pieces we thought they'd use in the final," he said.
"We replicated their centre-back and goalkeeper build-up routines, their 4-2-3-1 defensive shape with the striker cutting between opposition centre-backs and the 10 obstructing Liverpool's 6. Vinicius mimicked [Christian] Eriksen, Bernardo acted more like [Dele] Alli and Jose Gomes was [Harry] Kane.
"We had to adapt to that 4-2-3-1 shape, both defensively and in possession, with two midfielders dropping close to the centre-backs during build-up to try and attract Liverpool's press. "Tottenham would ideally want to attract Liverpool players closer to their box, so after a couple of passes between centre-backs and goalkeeper they can then attack the space in behind with their forwards and full-backs.
"We ended up just making slight tweaks to our regular system. A midfield triangle with Alli moving closer to the opposition centre-back (with Kane next to the other), Eriksen moving inwards to draw the full-back in while [Kieran] Trippier covers the wide space. Much like with [Heung-min] Son and [Danny] Rose on the left.
"Klopp complimented us - 'When you dropped your centre-backs to build-up we immediately set up the same press we used against Manchester City and you still managed to surpass it three or four times!'"
On the night, Liverpool cruised to victory, helped by an early penalty, which Mohamed Salah scored.
Divock Origi scored the second with three minutes remaining.
Six of his eight goals for Liverpool in the Champions League this season have been scored away from home. No player has ever scored more than six times away from home for Liverpool in a single season in European competition, while he is also chasing a record.
He could become the first player to score ten or more goals in multiple seasons for the club in the competition. The only other player to reach double figures for goals in a Champions League campaign on more than one occasion while playing for an English club is Ruud van Nistelrooy, who did it for Manchester United in the 2001/02 and the 2002/03 seasons.
Surely no amount of preparation from the hosts can stop such an in form striker…