Scotland international Gary Caldwell has John Hartson to thank for his Celtic career.

In 2004, the then Hibs centre back was making his name in Scotland when he came up against the ex-Arsenal striker. And Hartson was blown away by what he saw, calling Caldwell the best defender in Scotland during his five seasons at Parkhead.

In an interview with The Sun, Gordon Strachan emphasised the importance of taking the Welsh striker's advice. Caldwell had been sent out on loan many times after never being given a chance at Newcastle United before the Bhoys came calling.

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Strachan, Hoops boss from 2005 to 2009, explained: "[Caldwell] signed for nothing from Hibs. People were scratching their heads and asking why we’d bought him. The truth behind is that I’d asked John Hartson who the hardest centre-back in the league was. When we signed him, football was changing, and Gary was one of the first real ball-playing centre backs."

Caldwell went on to represent Scotland 55 times before his retirement from football in 2015. He was even voted Footballer of the Year and International Footballer of the Year by the Scottish Football Writers' Association. Caldwell went on to manage Wigan, Chesterfield, Partick Thistle and now Exeter City.