Former Arsenal captain William Gallas cannot understand why Patrick Vieira or Thierry Henry are not set to take over from Arsene Wenger.

The Gunners are expected to confirm the appointment of former Paris St-Germain boss Unai Emery as the new head coach later this week.

Gallas, signed by Wenger as part of the deal which took Ashley Cole to Chelsea on transfer deadline day in September 2006, believes Arsenal should have given the job to someone who already knows the club inside out.

“To be honest I’m a little bit surprised Unai Emery will be the manager. I expected to see the former legend players like Patrick Vieira or Thierry Henry,” Gallas said on Sky Sports News.

“Personally I didn’t understand why they didn’t go to speak to them and offer them that job.

“They did a lot for that club. When Arsenal won some trophies, it’s because that type of player was there. They know the club very well, all the fans like them.”

Gallas believes Spaniard Emery must hit the ground running.

He said: “I think for the next year, we will see what Arsenal are going to do because they will be under pressure.

“If Unai Emery goes to Arsenal, he will need to get results – and it won’t be easy.”