Player movements continued on Thursday under the AFL's free agency with Port Adelaide defender Troy Chaplin headed to Richmond and two-time premiership forward Shannon Byrnes switching from Geelong to Melbourne.

The Power had until Thursday afternoon to decide whether to match the Tigers' offer for Chaplin, who is a restricted free agent.

Chaplin's departure came a day after Port also decided not to match the offer that Fremantle made for fellow restricted free agent Danyle Pearce.

On Monday, the Tigers also recruited Adelaide veteran Chris Knights as an unrestricted free agent.

Byrnes is also an unrestricted free agent, meaning the Demons did not have to wait for a counteroffer from Geelong before signing him.

Port football manager Peter Rohde said they considered Chaplin too much of a long-term risk.

"Troy needed serious knee surgery towards the end of 2012 and while we hope he has many years of football left, we're not prepared to commit to the extent Richmond is," Rohde said.

"We would have liked Troy to remain at Alberton, but on terms suitable to Port Adelaide as well as the player.

"In fact, we had what we considered a fair contract in front of Troy and his management for a long period this year, but unfortunately they were unwilling to sign."

Chaplin has played 140 games for the Power since his 2004 debut.

Byrnes also debuted in 2004 and has played 108 games, including the Cats' 2007 and `09 premierships.

"He comes from a club that's had a lot of success, particularly finals success over a long period of time, and he's exactly the type of player who can assist our own playing group," Melbourne list manager Tim Harrington said.

"We see Shannon fulfilling a specific onfield role and pleasingly he was keen to come to Melbourne.

"We believe he comes here for the right reasons.

"He's not only a quality AFL player in his own right, but he's a player who can help many players on our list realise their own potential."