Young Essendon star Nate Caddy has been sent to hospital due to an elevated heart-rate in the Bombers' clash with GWS.
Caddy, who recently re-signed until the end of 2031 in a massive boost for the battling Bombers, didn't return to the ground after quarter time.
Essendon football boss Daniel McPherson was seen engaged in serious conversations with medical staff on the bench while Caddy was assessed in the rooms underneath Marvel Stadium.
The 21-year-old was soon ruled out with illness in the second quarter, with Essendon later detailing the heart issues.
The Bombers, who had won just one of their past 30 games, stunned the Giants at Marvel Stadium to win by three points in a thriller.