Justin Westhoff, Jasper Pittard, Cam O'Shea and Ollie Wines have recommitted to Port Adelaide.
Carlton will turn their attention to re-signing Bryce Gibbs after fellow midfield star Marc Murphy agreed to a long-term deal.
New St Kilda coach Alan Richardson faces a gruelling first year in charge of the struggling AFL club.
The AFL is considering taxing the big-spending clubs to address the gap between the spending powers of the big clubs and their low-budget rivals.
Collingwood vs Fremantle
GWS Giants vs Sydney Swans
Gold Coast Suns vs Richmond
Carlton vs Port Adelaide
Can Alan Richardson bring success to St Kilda?