Celtic's Ryan Christie has called for a rethink of Covid-19 self-isolation rules for footballers after revealing he tested negative "five or six times".
The 25-year-old and Kieran Tierney had to quarantine for 14 days as they were deemed close contacts of Scotland team-mate Stuart Armstrong.
After missing three Scotland games and Celtic's Old Firm defeat, Christie returned to face AC Milan on Thursday.
"It's nice to be back playing, finally," he said.
"It was a very frustrating two weeks to sit and watch games you feel you should be part of.
"I was tested five or six times and every one came back negative. I know there's a bedding-in period for the virus, but you need to wonder when it goes past common sense after countless negative tests.
"Maybe it's a rule that could be looked at. I get in normal walks of life that people come into contact and aren't getting tested and aren't in a controlled environment like we are."
Christie's frustration was compounded by Celtic not being allowed to field him in Saturday's defeat to Rangers, while Tierney played for Arsenal against Manchester City the same day.
Armstrong's positive test in the Scotland camp forced the trio to isolate after they had been playing computer games together, but Christie is adamant no guidelines were broken.
"It wasn't like we were all using the one TV or PlayStation," he added. "One of us was on that side of the room facing a TV, one on the other side, and one in the middle.
"We all had headsets on and weren't even looking at each other. The Scottish guys were measuring the distance between the seats and it was 3.8m so without even meaning it we were social distancing.
"Plus, through previous camps we were told by the Scotland doctor that it was okay to do that."