Gallas made the move to north London in 2006, leaving Stamford Bridge with Ashley Cole going in the opposite direction.
And the former French international has revealed that he didn’t know what to expect when making his first appearance for the Gunners – but that the attitude of the fans did surprise him.
Speaking to Four Four Two the 40-year-old, who later left Arsenal to join Spurs in 2010, was asked to recall his best memory for the Gunners – and chose a moment before making his first appearance.
He said: “I would say that my best memory at Arsenal is actually my first game against Middlesbrough.
“Because I’d arrived from Chelsea, the supporters would normally boo you.
“But when I was out on the pitch during the warm-up, they all applauded me. That was really nice – I did not expect that.”
The former French international retired from football in 2014 after spending one season playing in Australia with Perth Glory.