The Telegraph says the defender was forced into 14 days' quarantine after coming into contact with Scotland teammate Stuart Armstrong on international duty, who was then found to have contracted coronavirus.
Tierney looked to be ruled out of his clubs side's trip to The Etihad this weekend despite not testing positive for Covid-19 himself.
In addition, the 23-year-old also maintained he had observed strict social distancing guidelines when in Armstrong's company.
But Arsenal have now been successful in their bid to overturn the Lothian Health Protection Team's decision, leaving Tierney free to play in Saturday's fixture against Man City.
Tierney even undertook several tests - all of which proved to be negative.
He also handed over evidence that he did not come closer than the 2.8 metres allowed when playing video games with Armstrong, with both players doing so on their own devices.