Former Brazilian playmaker Juninho has told this month's issue of FourFourTwo that his time as a Celtic player was 'frustrating'.
Juninho, now retired, made his name with Middlesbrough, becoming a hero on Teesside during three separate spells with the club having scored a total of 32 goals for Boro.
His final appearance for Middlesbrough came in 2004, as he left the club in order to join Celtic, arriving to work under Bhoys boss Martin O'Neill that summer.
Seen as a big signing, the World Cup winner struggled to make an impact at Celtic Park, scoring just once in only 22 appearances for the club before heading back to Brazil with Palmeiras after less than a year in Scotland.
Now, ten years after leaving Celtic, Juninho has opened up on his time at the club, telling FourFourTwo that his spell with the Bhoys was 'frustrating' due to being misused by manager O'Neill.
"It was an awkward situation, and an especially frustrating one for me. I ended up in Scotland, but things didn't really work out for me. I had this issue with Martin O'Neill and his tactics. I still can't understand why he wanted me at Celtic. He used to play with a 4-4-2 and he asked me to play out wide with defensive responsibilities, but this was never my style. It didn't suit me and he knew it.
"Maybe inside his head he wasn't looking for the Juninho of the 90's, and maybe I'm to blame for that, but a manager should know a player's style - you have to use them in the right way. It was a shame it didn't work for me there, because Celtic is such a great club," he added.
One of the most disappointing recent signings
Celtic have had their fair share of duds in recent years; the likes of Mohamed Bangura, Lassad Nouioui, Amido Balde and Derk Boerrigter have all disappointed, but Juninho's lack of impact will frustrate Bhoys fans.
The Brazilian playmaker had demonstrated his ability during his time with Middlesbrough, and Celtic supporters were no doubt excited to see him arrive in Glasgow based on those performances.
However, Juninho - who was in his 30's at the time - couldn't replicate his Premier League success in Scotland, and whilst those other players were simply poor signings, Juninho had quality - but wasn't given the chance to show it.