Celtic boss Neil Lennon admits that he is proud to see Virgil Van Dijk succeeding with Liverpool.
The Dutchman was at Celtic earlier in his career, before going to Southampton and then joining Liverpool.
Lennon signed Van Dijk and spoke about him with Celtic legend Chris Sutton in a Daily Mail interview.
He said: "He was Rio Ferdinand in the making. He had all of those attributes - he was quick, composed, brilliant in the air in both boxes.
"Everything you're seeing now, at Premier League and European level, that's what I saw. I couldn't believe there was no English interest.
"I also couldn't believe he was at Celtic for two seasons! I thought he might have gone after the first."
Asked if he was envious that Premier League clubs had the funds to keep such players, Lennon went on to say: "It would be nice to be able to compete with them. I wouldn't say 'envious'. I like finding players under the radar.
"Van Dijk is the standout example. He goes for £12m to Southampton, then £75m to Liverpool, and now he's probably the best centre half in the world. We take pride in that.
"We take pride in Kieran Tierney going to Arsenal for £25m.
"There is a lot of untapped natural talent here. Ideally you'd love to hold on to these players because then we'd have a strong chance of achieving something in Europe."