Barry Ferguson reckons Shane Duffy's horror season at Celtic proves the Scottish Premiership is better than it's given credit for.

The Rangers hero recalls thinking Duffy would be a superb addition to the Hoops ranks as an experienced pro who had played in the Premier League down south and on the international stage.

But the Irishman - who this week headed back to parent club Brighton - made a number of high-profile and costly errors at Parkhead and struggled to adapt to the Scots top flight.

Ferguson told how Duffy is not the first player to fail and won't be the last. "I thought it was a great signing," Ferguson told Go Radio.

"I watched him at Brighton, he had the experience, he was Republic of Ireland captain. But it just shows you that when very good players come up to Scotland, some struggle to settle.

"Believe me when I say this, and I have seen it with my own eyes with a lot of players, it is a tough league to play in, it is not easy.

“Sometimes you get away with it at home, but when you go away from home and go to places like Easter Road, Tannadice, and Pittodrie – difficult places to go and play. I can go through every single team in the SPFL and if you are not ready and up for it, you get caught out, believe me."