Arsenal got a huge bargain when they signed Kieran Tierney from Celtic for £25m reckons John Hartson.
The former striker, who played for both clubs, is a huge fan of the tenacious left-back.
He pointed out that Manchester United paid Crystal Palace £50m for a similar but less experienced player in Aaron Wan-Bissaka last summer.
And although Tierney has had an injury-hit start to his Gunners career, Hartson is surprised that Celtic didn’t hold out for more cash.
“Arsenal probably got him on the cheap if you look at the fact Manchester United paid £50m for Aaron Wan-Bissaka,” he told the Daily Record.
“Also, average players are going for £30m or £40m and Kieran is certainly not average.
“Celtic could have held out for another £5m or so but it is still good money they have banked, especially due to the fact he has come through the ranks and hasn’t cost the club a penny.
“He is worth £25m and he can excel in a different league because there’s a perception the Scottish league is just not as good.”
The Scotland international did not leave Celtic with the blessings of the majority of fans when the transfer was finally agreed.
But Hartson is in no doubt that Tierney has made the right move at the right time.
“He is 22 and obviously felt a move to Arsenal in the Premier League would be good,” he continued.
“I lived up in Glasgow and the Celtic fans think you are going to be there forever.
“It’s a wonderful club with a brilliant support and I have a great rapport with them but the timing was right for Kieran to go. Top players all leave at some point, even the great Henrik Larsson left.”
Tierney has played just twice for Arsenal since his transfer but is confident of enjoying a run in the team after the international break.