TOBY Greene and Matt de Boer were joining in the usual pre-game warm-up with their Greater Western Sydney teammates when the news landed just over an hour before the first bounce that they wouldn’t be allowed to take the field in the Sydney Derby.

The Sydney players were also starting to warm up when the Swans' football manager Charlie Gardiner received a call to explain that Callum Mills, Harry Cunningham and their medical sub Colin O'Riordan would have to be pulled from the line-up.

The five players had attended the Wallabies v France rugby match in Melbourne last Tuesday, which the Victorian health department had upgraded to a Tier 2 COVID-19 exposure site.

Under the Queensland Government’s rules that both clubs are now living under, the five players, plus another three players who hadn’t been selected for the match and six staff members across the two clubs, were now required to isolate for 14 days.

"Charlie Gardiner came in and said there is a possibility that could be the case, so I quickly got on the phone and rang the players back at the hotel,” Sydney coach John Longmire said after the match.

Most of the players that hadn’t been selected for the Sydney Derby had played in a scratch match the day before, including James Rowbottom who had his first full-length hitout since pulling up sore from the Swans’ match against Port Adelaide in round 15.

"We got the medical staff in and went through the players that we thought could back up," Longmire said.

"We thought about who could come in and play, who has played a bit of senior footy. Plus, who we thought was physically not beaten up, it was a pretty tough game in trying conditions up here in our reserves.

"Rowey is a pretty tough cookie and gets on with it. He's pretty strong mentally. Dylan Stephens only played a half, so that made his decision a bit easier. [Ben] Ronke is just coming back from injury so we had to bring him in as a sub.

"I rang them and told them to get in the car and come to the ground and get changed."

Rowbottom was at the club’s hotel on the Gold Coast and getting ready to head to Metricon Stadium to watch his teammates play against the Giants when the call came through.

The Swans’ midfielder told the club’s website that the message was: "Get your gear on, it’s been a sh**show down here, you might be playing."

Rowbottom said after the match: "I jumped out of the shower, got dressed, my girlfriend came upstairs two or three minutes later and said, 'What are you doing, aren't we leaving in an hour?'. I said: Nah, I think I'm playing."

The Swans’ late additions arrived at the stadium about 20 minutes before the first bounce, with little time to physically or mentally prepare for the match.

Rowbottom didn’t have a possession in the opening term but Stephens was able to have an immediate impact with seven disposals for the quarter.

"It was a bit rattling [in the first half], still a bit tired from yesterday. I was just trying to play a role while I was out there,” Rowbottom said.

It was a bitter blow for the Giants to lose superstar forward Greene for the crucial clash, especially at such short notice, but coach Leon Cameron explained after the match that the club “jumped into action and brought some troops over from the hotel which was about 10 minutes away.”

Prized draftee Tanner Bruhn was added to the starting 22 in place of Greene, while Zach Sproule replaced de Boer as the Giants’ medical sub.

Bruhn was lively early and looked set to make the most of his unexpected opportunity, as he gathered six disposals, kicked a goal and helped set up another in the Giants’ blistering opening term. He ended the match with 11 disposals from 92 minutes of playing time.

For the Swans, Rowbottom finished with eight touches from only 56 minutes of game time and Stephens gathered 12 possessions in 81 minutes, as the Swans overcame a slow start and 35-point deficit in the second term to end the bizarre day as 26-point winners.

"I was tired towards the end there but the momentum helps when you're winning,” Rowbottom said.