Celtic skipper Scott Brown believes that his former teammate Kieran Tierney has an immensely high ceiling.
Tierney completed a deadline day move from Celtic to Arsenal.
Despite moving from the Scottish champions, Tierney left nothing but positive impressions on the club's fans and players.
And Brown believes he could go on to sign for a club like Barcelona or Paris-Saint Germain.
"You don't know what could happen," Brown told The Herald.
"He could have a fantastic couple of seasons and end up at Barcelona or PSG or wherever."
