St Kilda have been forced into making two changes for Sunday's clash with Port Adelaide in China.

A sickness infected a number of Saints over the weekend, causing three players and coach Alan Richardson to train away from the group on Saturday.

The Saints have confirmed that Dan McKenzie and Jonathon Marsh have been ruled out of the match due to illness, with Nick Coffield and Darragh Joyce taking their place in the side.

St Kilda general manager of football Simon Lethlean said the rest of the playing group were healthy.

โ€œWeโ€™re ready to go,โ€ Lethlean told the clubโ€™s website.

โ€œMcKenzie and Marsh are feeling better this morning but we made the call to leave them out of the side given their preparation was compromised.

โ€œCoffield and Joyce have trained fully over the past two days and like the rest of the group are really excited to get out there.

โ€œRicho and the other guys who missed yesterdayโ€™s captainโ€™s run are fully recovered, as expected.โ€