Former Brisbane captain Tom Rockliff has officially joined Port Adelaide after the Lions opted not to match the Power's free agency offer.

In return for losing Rockliff, the Lions will receive pick No.18. The 27-year-old played 154 games for Brisbane after being selected in the 2009 pre-season draft.

โ€œI met with Ken Hinkley, Travis Boak and some other key people at Port Adelaide after the season and was really impressed,โ€ Rockliff told Port Adelaide's website.

โ€œI think the club can be great for me as a footballer and I think I have a lot to offer the club too.

โ€œPort Adelaide is coming off a strong season and everyone is optimistic about what we can achieve in 2018.โ€

Rockliff played 20 games this season, averaging 24 disposals, six tackles and kicking 16 goals.

Port list manager Jason Cripps said the club is thrilled to secure the experienced onballer's signature.

โ€œHeโ€™s an elite ball-winner, a good decision maker and is versatile with his ability to impact in the midfield and up forward,โ€ Cripps said.

โ€œTom is a recognised and experienced leader who will provide invaluable direction on-field, [he] had several options and weโ€™re pleased he chose us.

โ€œWeโ€™re confident Tom and the club will work together and in time prove this was the right decision.โ€