Smith used to play for the Gunners, but he has still been highly impressed by Bertrand’s performances.
The Saints left-back is due to play for England against Spain on Friday evening, and Smith has warned that the fixture will expose any flaws that the former Chelsea defender does have.
"Looked the part against Estonia in early October," he said. "Quick and mobile, he might be a better defender than Kieran Gibbs. This match, however, should find any flaws."
Bertrand missed much of the early part of the campaign through injury, but he is clearly highly regarded by the Three Lions’ staff, as he has come straight back into the national squad.
England are well stocked at left-back, but Bertrand has been able to fend off competition from the likes of West Ham United’s Aaron Cresswell and Tottenham Hotspur’s Danny Rose so far.
The 26-year-old will be eager to show his class against Spain, too, as he has a chance to stake his claim for a regular spot in Roy Hodgson’s starting line-up.
Everton’s Leighton Baines is generally considered to be England’s first-choice left-back, but with the more experienced full-back out injured, Bertrand has a good opportunity to impress.