PORT Adelaide has pulled a major surprise with West Australian midfielder Domenic Cassisi appointed its captain for 2009.

The 26-year-old becomes the club's fourth official captain since it entered the AFL in 1997, following Gavin Wanganeen, Matthew Primus and Warren Tredrea, who led the Power to the 2004 premiership.

Tredrea stepped down from the position at the end of last year and Kane or Chad Cornes were strongly tipped to replace him.

Kane Cornes and Shaun Burgoyne have been named joint vice-captains.

Club president Brett Duncanson said Cassisi was the clear leader of an impressive group of candidates.

"While we had an outstanding field of candidates, in the end it was a clear decision for us. Dom has emerged very, very strongly over the last two years, and in the last 12 months in particular," Duncanson told portadelaidefc.com.au.

"His club-first and selfless attitude, both on and off-field, has won the absolute respect of the playing group, management and coaching staff."

Cassisi, who has played 128 games since he was drafted in 2000, is humbled by the appointment.

"I take great honour in being named captain of the Port Adelaide Football Club," he said.

"The support I have received from Choco (coach Mark Williams), the leadership group, the coaching staff and my teammates has been overwhelming to say the least.

"Their support – along with the support of my fiancé and our families – has been vital to me being given the opportunity to lead this great club of ours."

Williams said Cassisi's appointment marks a new era for Port Adelaide.

"Dom will be an outstanding captain for this football club," Williams said.

"He is a typical Port Adelaide captain – a hard and tough player who leads by example.

Following club tradition, Cassisi will vacate his No. 25 guernsey to wear No. 1.