Derby County player-coach Wayne Rooney admits he's a fan of Liverpool's attack.
Mohamed Salah has netted 20 times for the third successive season while Sadio Mane's 18-goal return has seen him among the favourites for individual honours this season.
But Rooney has pointed to the contribution of Roberto Firmino as being integral to Liverpool's celebrated attacking triumvirate being unparalleled at present.
"Scoring is often down to players working together and the Liverpool front three are the perfect example," said Rooney, writing in The Sunday Times.
"Salah and Sadio Mane provide the depth by pushing teams back which allows Firmino to come deep for the ball, the opposition centre-backs relax and suddenly the other two make diagonal runs at incredible pace to attack the space.
"It reminds me of how Roma used to play with (Francesco) Totti as No 10 and two quick runners attacking the box from wide.
"It pains me to admit it, but Liverpool are the best attacking unit in world football at the moment."