The Russia-born doubles specialist was on flight QR7493 from Los Angeles, sharing the chartered plane with three people who tested positive to COVID-19 after landing in Melbourne.
Now, as one of the two-dozen players aboard the flight deemed "close contacts" of the infected trio, Sitak is effectively in solitary confinement at the View Melbourne, an inner city hotel converted into a quarantine facility.
Unlike other players who arrived safely and have the luxury of leaving their hotels to train five hours a day, the 34-year-old cannot even open his door for the threat of a $15,400 fine under Australia's strict quarantine regime.
"Everything that I did in the off-season...I had six very good weeks of training, it’s not completely ruined but it’s not the same now," he told Reuters in an interview.
Sitak gave Reuters a virtual tour of his room, a bland but comfortable enough space with a window that overlooks a city-scape.
Other players got creative with their quarantine training regime.
Tunisia's Ons Jabeur has been keeping up with her training by hitting a tennis ball against a mattress propped up on the wall of her hotel room.
Another tennis player was seen putting up signs from his window saying "I need practice" and hitting a ball on the window at his quarantine hotel.