Mikel Arteta's side have started their Premier League campaign with a 2-0 victory against Crystal Palace at Selhurst Park.
Gabriel Martinelli opened the scoring for the north London side with an own goal from Marc Guehi doubling the lead for them late in the game.
Saliba, who was signed by the Gunners three years ago from AS Saint-Etienne, finally made his debut for the club on Friday night.
In his very first game for the club, the Frenchman made quite a mark in the game, which was enough to impress club legend Keown.
The former Premier League winning defender claimed that Saliba came up with a 'Man of the Match' display against the Eagles. He told talkSPORT:
“Saliba – the fella’s been at Arsenal now for three years and it’s the first time we’ve seen him."
“I think he should take a bow really because he deserved an opportunity far sooner than he got tonight."
“If it was me given the choice, I’d go with Saliba for Man of the Match."
Keown has insisted that Arteta must have seen something special in the 21-year-old in pre-season that prompted him to use £50 million signing Ben White at right-back to accommodate Saliba. He added:
“I mean they paid £50 million for Ben White and Ben White’s having to play right-back because obviously the manager’s seen something in this player in pre-season, and why not?"
“I think actually it’s paid off and now we do have real competition in that central defensive position.”
Saliba could cement his place in the Arsenal backline
It's quite remarkable that a player of Saliba's caliber had to wait three years for his Arsenal debut.
The Frenchman has spent the majority of his Arsenal contract away on loan in France with AS Saint-Etienne, Nice and Marseille in that order.
While many criticized Arteta for loaning the young defender three times, he should be credited for the development Saliba has had in his homeland.
He was awarded 'Ligue 1 Young Player of the Year' last season for his display at Marseille and has even earned five caps for his country. He made 36 Ligue 1 appearances last season, helping his team maintain 13 clean sheets.
Saliba looked solid and assured against Crystal Palace and has already shown that he can become the defensive lynchpin of the Arsenal side.