McGrath did not line up with her team-mates during the national anthems and was seen sitting by herself in the stands wearing a face mask while the other Australian players sat in their dugout. However, she came into bat at No. 4 without a mask on.
Commonwealth Games Australia confirmed the news of McGrath's participation in a statement during play on Sunday, saying they had consulted with a tournament expert team and match officials, before McGrath was permitted to take part.
"McGrath presented to team management with mild symptoms on Sunday and subsequently returned the positive test," the statement said. "She was named in the starting XI at the toss and the International Cricket Council (ICC) approved her participation in the final.
"Cricket Australia medical staff have implemented a range of comprehensive protocols which will be observed throughout the game and for post-match activity, to minimise the risk of transmission to all players and officials."
It is understood to be the first case in international cricket when a player known to have Covid-19 has taken part in a match, and comes after it emerged that the participation of Covid-positive players across all sports at the Commonwealth Games in Birmingham would be assessed on a case-by-case basis. Factors considered include the severity of an individual's illness, how heavily infectious they are likely to be, and whether they compete outdoors or in a confined space.
The toss was delayed while consultations on the matter took place between various governing bodies but play started at Edgbaston on time.
When Meg Lanning was run out by Radha Yadav in the 11th over of Australia's innings, McGrath came in at No. 4 as usual and spoke with batting partner Beth Mooney upon arriving in the middle. The pair had batted together for an extended period on the previous evening, putting on 56 runs as Australia defeated New Zealand in the semi-finals.
On this occasion, however, McGrath's stay at the crease was brief, ending when she cut Deepti Sharma towards backward point, where Radha Yadav took a blinder of a catch diving a long way to her left.
McGrath, who faced four balls for her score of 2, trudged off the field, back towards the stand where she had been sitting earlier, some distance from the dugout.
Australia's cricketers have followed some of the strictest Covid-prevention protocols among athletes in Birmingham, wearing face masks during all post-match interviews and at any time they are indoors other than in their rooms or exercising. They had not been allowed to go and watch other sporting events at the Games until Friday when that was relaxed.
"The CGA has maintained a comprehensive Covid-19 risk mitigation strategy for the Birmingham 2022 Commonwealth Games, with testing protocols over and above those required by the Birmingham 2022 Organising Committee," the Commonwealth Games Australia statement added.
After the match, Harmanpreet Kaur, the India captain, said that her side felt comfortable playing in the circumstances.
"They informed us before the toss," she said. "That was something not in our control because the Commonwealth has to take the decision. We were okay because she [Tahlia McGrath] wasn't very ill, so we just decided to play. We had to show the sportsman's spirit. We're happy that we didn't say no to Tahlia because that [missing the final] would have been very hard-hitting for her."
Mooney said she was comfortable with the way the situation was handled.
"I think it was handled extremely well from from Cricket Australia's point of view, in terms of having protocols in place and making sure everyone in the team was comfortable that she was playing," Mooney said. "They did all the right things. Our medical staff did all the right things in making sure we were keeping everyone safe. Towards the toss, it became a bit hairy there for a while, but I think it's no different to someone playing if they've got a cold or flu.
"So from my perspective, the right decision was made and we just went out and played. It wasn't within our control. The people who are paid to make those decisions made them and we had no control over that."