Kieran Tierney will prove to be a bargain for Arsenal at £25 million, according to former striker John Hartson.
The 22-year-old, who arrived at the Emirates Stadium from Celtic this summer on a five-year deal, had been delayed in making his debut after picking up a hip injury.
The Scotland international finally made his first appearance against Nottingham Forest in the Carabao Cup following a hip problem and excelled in the Gunners' 4-0 victory against Standard Liege in the Europa League.
Arsenal negotiated with the Scottish champions for the majority of the summer before finally agreeing to pay a £25m fee.
And Hartson believes Unai Emery has picked up a bargain in comparison to other transfer fees paid this summer.
"Arsenal probably got him on the cheap if you look at the fact Manchester United paid £50 million for Aaron Wan-Bissaka," he said.
"Also, average players are going for £30 million or £40 million and Kieran is certainly not average.
“Celtic could have held out for another £5 million 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 £25 million and he can excel in a different league because there’s a perception the Scottish league is just not as good.”
Tierney could make his Premier League debut for the north London side when they face Sheffield United on October 21.
