Reigning Brownlow medallist Ollie Wines remains in hospital with an irregular heartbeat after being subbed out of Port Adelaide's round-four AFL game.
Wines felt unwell during the Power's 32-point defeat against Melbourne at the Adelaide Oval on Thursday night.
The star midfielder left the game at halftime after experiencing nausea and dizziness.
Port on Friday confirmed the 27-year-old is undergoing tests in hospital and a cause of the heart irregularity will hopefully be determined in coming days.
"Wines remains well and in good spirits," a club statement read.
"A further update will be provided once more information becomes available."
Wines' poor health capped off a horror night for Port where they fell to 0-4 this season after recording their first goalless first-half in club history.
He has played 185 games for Port since debuting in 2013 and was awarded the AFL's highest individual honour last season, polling three more votes than Western Bulldogs star Marcus Bontempelli.
