PORT Adelaide hasbeen dealt a blow on the eve of the NAB Challenge with ruckman Jarrad Reddenruled out for at least eight to 10 weeks after undergoing knee surgery. 

The 23-year-oldbattled shoulder, hip and knee issues last season and underwent five bouts ofsurgery between last June and Christmas. 

He previously toldAFL.com.au he had "tweaked his knee" while running at a local oval onholiday after the 2013 season. 

Redden's latestsurgery will sideline him for at least eight to10 weeks. 

Power coach KenHinkley said Redden's knee had failed to improve and surgery was the bestoption to ensure the 205cm ruckman played a part this year. 

"Thisis a decision based on getting Jarrad right so he can play as much football aspossible in the 2014 season. 

"He'llnow dedicate himself to his rehabilitation and work closely with our medicalstaff." 

Twitter:@AFL_Harry