According to an official statement from the Waverley Park side, the 20-year-old is currently in isolation with his close contacts following suit while they await test results.
The father-son selection will now quarantine as per the AFL and Victorian Government’s quarantine protocols.
Hawthorn revealed that Maginness was present at the club's headquarters on Monday of this week, however, he was asymptomatic at this point.
Still, the midfielder's health had worsened to the point of requiring testing by Tuesday morning.
Within said statement, Hawks Chief Executive Officer Justin Reeves explained that he was more than content with Maginness' level of responsibility.
“I want to commend Finn for his diligence in getting a test at the first sign of symptoms, informing our club doctor and protecting his teammates and our staff. As a club we are taking every precaution to ensure the health and wellbeing of our staff and the broader community is maintained,” Reeves said.
“Appropriate wellbeing supports have been put in place to support Finn and those who are isolating as a result of this case.
“Every staff member and player that needs to be tested is being tested and the clear processes the club and AFL have in place has ensured that those who need to isolate are isolating.
“Football clubs are no different to rest of the community, and these kinds of situations will continue to occur as our community continues to open up. This highlights the importance of being vaccinated and getting tested as soon as you have any symptoms."
The Hawks have also claimed that each of their listed players are either fully vaccinated or are in the process of awaiting their second jab.