St Kilda defender Dylan Roberton can expect at least a couple of games out of the AFL as doctors try to pinpoint what caused his collapse during the Saints' game in Geelong.
St Kilda are confident it was some sort of heart issue and Roberton will face ongoing tests.
While Roberton said on Monday he hoped to miss only one game, coach Alan Richardson said no risks would be taken.
"We know he's had some form of heart murmur, if you like, (and) that he's feeling really good," Richardson told Fox Sports.
"But the reality is, at this stage, there's a lot of testing still to go.
"He's mentioned that he'll miss this week and get to training next week and possibly play.
"I reckon that's probably unlikely, unless the doctors can find something and say 'No, he's right to go'. I'd imagine that's going to take a while."
Richardson and Geelong coach Chris Scott spoke of their relief that Roberton recovered quickly after he collapsed during Sunday's game between the clubs, which the Cats won by 47 points.
Roberton was released late on Monday after spending the night in Geelong's Epworth Hospital.
"It was a really distressing moment for everyone," Richardson said.
Roberton was in good spirits as he spoke to reporters after leaving the hospital.
He will definitely miss Saturday's game against Greater Western Sydney at Etihad Stadium.
"This week I'm ruled out, just as a precaution," Roberton said.
"I will do all the testing and then hopefully back on the track next week.
"It was a bit of a scare, probably more so for family and friends. I was fine straight away."
Roberton has limited memory of what happened.
In the second term, he was standing on the edge of the square at a centre bounce when he suddenly collapsed.
"I just remember watching the ball go up and getting dizzy but that's about it," Roberton said.
Saints football boss Simon Lethlean said the defender had not reported any related health issues before the match and had not suffered any major knocks during the game.
Teammates and club medical staff quickly went to Roberton and he was able to walk from the field.
"Hopefully it's a one-off event and it doesn't happen again," Lethlean said.
The Saints football boss said Roberton was dealing with the scare well.
"He's a pretty relaxed character, Dylan, so he headed off the ground and told a few people that he was feeling a bit dazed and a bit bleary-eyed," Lethlean said.
"You don't get that much more from Dylan about that sort of stuff. He's a pretty casual, professional guy."
The Saints have kept Roberton's teammates updated.
"They were a bit shaken up, as you would be if you see a mate go down like that," Lethlean said.