The 21-year-old defensive midfielder, who initially joined Newcastle in the summer on loan from Borussia Dortmund, has long been followed by Benitez who feels he can do a similar job to what Alonso did when they were together at Liverpool.
Benitez initially signed Alonso from Real Sociedad in 2004, with the Spaniard going on to play an integral role as the Reds clinched a fifth European Cup, and having watched Merino close up he’s favourably compared him to his past student.
“There are similarities,” he said, as reported by the Evening Chronicle.
“I will tell you, though it maybe sounds stupid, that they are both Basque – from the Basque country.
“They are similar because of the position they are in and the way they read the game. Alonso’s long passing was better but Merino is more mobile and more dynamic.
“I’ve been tracking him for a while now. We knew him when he was in the Under-21s,” he added.
“With him he hasn’t been playing regularly for a while so his job is to keep going, keep training, get as many minutes as he can under his belt and he will get better.
“Yes [he’s adapting to the pace], there have been a couple of situations [where he’s been caught out] but he is very dynamic. He is always moving.
“It’s a question of understanding the game here. He has natural composure on the ball.
“There were a lot of players I had at Liverpool in the beginning who came from Spain. It’s always difficult at first when you have quality they eventually adapt to the pace of the game”
Merino became the club’s fifth major acquisition of the summer as they prepared for life back in the Premier League.
He joined on the back of representing Spain at the recent U21 European Championship, attracting number of clubs, but it was Newcastle that won out.
Nominally a defensive midfielder, though capable of playing in central defence, Merino joins having spent one season with Dortmund whom he joined from boyhood club Osasuna.
He’d ultimately feature across nine matches for The Black and Yellows, with all but one of them coming in the Bundesliga, under then manager Thomas Tuchel.
Opportunities at one of European football powerhouses was sparse and Benitez is hoping the potential he showed at Osasuna – which first attracted BVB – can be fulfilled at the North-East club.