Powell started his career at Cardiff before stints at Richmond, Leeds Tykes and Gloucester. He returned to Cardiff Arms Park in 2006 and went on to play 80 games for Cardiff Blues.
But Powell, tour his achilles in the Magners League defeat to Leinster in March.
Blues Head Coach Dai Young was disappointed with the the news but took the opportunity to wish Powell all the best for the future.
"Although he has been around a long time he is still quite young," said Young.
"Unfortunately it was a really nasty injury. He's worked hard to get back but with his position it's not one he's getting over.
"It's a big shame , he's played a lot of games for us and we're all sad to see him finish this way."
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