Jamie Carragher has labelled Premier League transfer target Matthijs de Ligt "unbelievable", "a leader" and "top class".
The Holland international, who comes up against England in the Nations League on Thursday night, has been strongly linked with a transfer away from Ajax this month.
Europe's elite including Man United, Liverpool, Juventus, and Barcelona have all registered interest in the centre-back in recent weeks, but none, as of yet, have been able to secure his siganture.
Carragher is a big fan of the 19-year-old, who guided his Ajax side to the semi-final of the Champions League this season while wearing the captain's armband.
Discussing why he's better than other quality defenders his age, Carragher told Sky Sports: "It's unbelievable what De Ligt is doing at 19-years-old. The performances we saw him give in the Champions League were outstanding,
"But it's not just his ability – there's obviously been a lot of great young defenders, teenagers we've seen over the years with talent – but also his leadership qualities.
"I saw him giving a speech at the end of the season on a stage, speaking like he was 29, not 19. To be captain of Ajax and with them getting to where they got to this season, he's clearly a leader and top class."
He added: "He's got the physical attributes too. I played that position as a young kid and sometimes you can make mistakes by getting knocked about if someone is too strong for you or too quick for you because you're not fully developed physically.
"But that's not a problem for De Ligt at all, he's a man. He looks like he's 24 or 25. That's a massive advantage for him at a young age.
"There's no guarantee with any player but you look at De Ligt and, for me, it's almost like a guarantee he's going to be a top player."
