Controversial forward Ahmed Saad was subjected to howls of abuse by Gabba fans but St Kilda insist his back-door selection was above board.
Saad, under investigation by the AFL for submitting an irregular drug sample last month, played in Saturday night's 31-point loss to Brisbane despite initially being overlooked in the Saints' 25-man squad named on Thursday.
St Kilda coach Scott Watters denied he'd done anything wrong by elevating Saad late as a gastro bug swept through his team, affecting the three named emergencies.
Saad was included as an emergency on Friday afternoon when Trent Dennis-Lane was scratched and then elevated to the team just before play as Jack Newnes was ruled out with illness.
But Watters was guarded about whether it was intended Saad was always going to play, and the club protected him from a potential firestorm.
"We pick our side and like every club we have the opportunity to change emergencies as we go," he said.
"The process ... is AFL approved and we followed that to the letter.
"The reason why Jack Newnes, Trent Dennis-Lane, Seb Ross, (and Tom Hickey) who were emergencies, don't play, is they were crook as dogs for 24-48 hours.
"(There was a) pretty good shot of gastro going through our boys.
"He (Saad) was brought in late because we had illness, that's it."
Saad didn't escape the attention of the Gabba crowd, receiving a torrent of abuse as he lined up an early set shot from the boundary line then calmly slotted the goal.
The 23-year-old finished with two goals from three touches in a display Watters described as an "average performance".
But Watters was keeping mum about Saad's case and his mindset heading into the round 17 match.
"It's confidential that whole situation, and unlike many throughout the press I'll maintain that level of confidentiality," he said.
Despite a positive test on his A sample, reportedly for a powdered stimulant in an energy drink, Saad is eligible to play while waiting on the results of his B sample.
Watters said both Rhys Stanley and ruckman Ben McEvoy were also affected by the gastro bug, but Stanley's night finished at halftime after he injured his collarbone in a marking contest.
Stanley was booked in for scans on Sunday.
