Queens Park Rangers legend Taarabt was speaking exclusively to talkSPORT about the forward who is on the brink of joining Liverpool for an initial fee of £64million.
The 22-year-old scored 34 goals in his second season in Portugal, six of which caught the attention in the Champions League against three of Europe's biggest sides.
Taarabt, who also played at Tottenham and Fulham before finding a home in Lisbon, knows the striker as well as anyone, and was impressed from the first day.
He explained: "Last season when Benfica bought him from Almeria nobody knew him really but it was already a big fee, a lot of people were surprised.
"But when we saw him in the first training we understood that he was going to be one of the best strikers in the world.
"He has that mentality of South Americans, he likes to win, he's a winner, he fights, he's very very fast and strong as well."
Any doubts that Nunez will struggle with the step up to English football have been quashed by Taarabt, who revealed Reds boss Jurgen Klopp had a secret word with the striker back in April.
When asked if Nunez can score in the Premier League, Taarabt said: "100 per cent, he showed it in the Champions League you see the two games that he had against Liverpool and he was amazing.
"Even after the game, the second leg, Klopp goes to him direct and said what a player he is.
"Darwin has a mix of [Edinson] Cavani and [Luis] Suarez, he can jump, he can go behind, for me he's a mix of both.
"I mean 34 goals, six in the Champions League, two against Barcelona, Bayern Munich and two against Liverpool and he's 21-years-old.
"So the most important thing is he keeps his head and he's focused and I think the only thing [problem] that could happen for him in Liverpool is the language barrier.
"I like the strikers that are selfish, that when they're in front of goal they just want to score, just finish, and he has that, if he doesn't score he's not happy.
"But he was helpful for the team. He works so hard, he's fit, if you see his body he's a real athlete, he's a machine, so for me in the Premier League he will score goals for sure."
Taarabt also explained why players signed from Portugal's Primeira Liga seem to do so well in English football.
Luis Diaz was signed by the Reds from Porto in January and began his time with the club on fire, while Manchester City have had extraordinary success with players from the league.
Taarabt explained: "Two years ago they called me for Rubin Dias who was playing with me and said 'do you think in the Premier League he will do it?' The first year he finished as the best player in the league.
"I told them it will be the same [with Nunez] because at Benfica, they make you in the head focused on your career, going to the gym before, after [training], you're professional, you know how to eat, and when you're at a young age and you already have that…
"If you compare that to me, if you're in the Premier League at 17, you have your contract, you do what you want, you're in London and it's difficult.
"These guys, they arrive and they are already prepared, because for me Benfica is the club that has the best conditions for young players, he's not the first one, [Joao] Cancelo, Ederson, Bernardo Silva… I can go on non-stop, every year it's the same."