Quinnell began his senior career with Llanelli RFC at 18 years of age and after that joined Richmond for three years before joining Cardiff RFC in 1999 where he played 54 games for the Cardiff club between November 1999 and May 2002.
He established himself as the backbone of the pack but moved on to Saracens and Worcester for a short while, before returning to the Arms Park in 2003.
Quinnell won his first international cap as a flank forward against Fiji in 1995 at the age of 20 and now has 32 international appearances to his name. He was a member of the Rugby World Cup squad in 1999 and has toured with Wales to Argentina and Japan he was also a member of the team that recorded the famous 32-31 victory over England at Wembley in 1999 and played in every game of the 10 match winning streak.
Cardiff Blues Director of Rugby Dai Young said: "Craig has always been very supportive to me and has always gone out and given his best on the field. He's been very influential in helping us with moving things forward off the field and he will be missed.
"As a player I always wanted to play with him rather than against him and we go back a long way both as a coach and as players, personally I think his best international performance goes back to the victory over England in Wembley.
"He's a player who always gave everything and the power that he brought to the game was unmatched by any second row that I played with. His activities off the field with charities and children should also be mentioned.
"He's very approachable person and I don't know anybody who doesn't like him ... apart from some of the opposition. He will be missed greatly by rugby in general, and I'd like to thank him for all his support and effort throughout my coaching career."
Quinnell added: "Obviously I'm really disappointed I'm never going to play again whether professionally or even a fun game. The Consultant has told me I could be one hit away from a wheelchair and that really hits home how lucky I have been and I am to hopefully able to continue to play other sports such as golf and squash as well as lead a normal life.
"I'd like to thank everybody who has been involved with me in my career ranging from Mike Bieri the kit man, to people like Graham Henry and Dai Young, to the numerous players I've played with and the coaches I've played under.
"I've had a total of 6 years in the capital with many ups and downs in that time, but I've enjoyed every minute. I can't think of a better place to have finished my career than here. I'd like to thank all the Blues faithful who have cheered me on as well as thanking all the opposition fans who have booed and heckled and driven me forward over the years.
"It's a very sad time for me and it's going to be hard to adjust to life without rugby. Once again I'd just like to thank everybody."