Liverpool enhanced their quest for an unprecedented quadruple this season with a 2-0 win over Villarreal in the semi-final first leg of the UEFA Champions League at Anfield on Tuesday.
Villarreal defended resolutely but were undone by two quick second half goals; Pervis Estupinan putting through his own net and Sadio Mane adding a second.
Liverpool will be overwhelming favourites to make the final in Paris when they travel to Spain for the second leg next week.
Jurgen Klopp's men already have the Carabao Cup in the bag while they have an FA Cup final date with Chelsea to come next month.
The Reds are a point behind Manchester City in the race for the Premier League title with just five games left to play.
"This is the best Liverpool team I’ve ever seen. They’re relentless with and without the ball," Ferdinand beamed to BT Sport after the final whistle.
"It’s the way they press teams, the energy, effort, application, you marvel at it.
"That [the quadruple] has got to be the aim. They are going to set themselves the target.
"If they achieve it they’re immortal, they are above anyone that has played the game in this country. Whether they can achieve it remains to be seen. But they’re ticking boxes along the way at the moment."
