The left-back is out of favour at the Gunners and did not earn a permanent move to Real Sociedad after last season’s loan spell in Spain.
Tierney has always admitted to missing Scotland, but said to The Athletic that he would only go back to Celtic if he could play a key role in the team.
The Arsenal defender said: "I don’t regret it. I still miss it but I knew life would never be the same. I was living my dream.
"Being a footballer is the dream but playing for Celtic was the ultimate. I left that to go and challenge myself in the Premier League and come up against the best to see how I’d cope. If I go back, I want to be feeling how I did there before.
"I’ll be a different player to what I was, as I’ve been away for years, but I wouldn’t want to go back if I wasn’t feeling 100 per cent in my body. I know the intensity and the demand to win so, if I go back, it will be when I’m still feeling good.”