The France worldwide has scored 14 goals in his last 24 games for the Gunners, including a brace in a 5-1 win at Fulham before the global break.
But Emery warned the increasingly optimistic fanbase against getting carried away.
"He is very important for us because he is our captain", the Arsenal boss told the club's website.
The north London outfit lost 2-0 to defending Premier League champions Manchester City in their opening fixture of the campaign before Arsenal slumped to a 3-2 loss to derby rivals Chelsea FC at Stamford Bridge back in August.
Arsenal are on a nine-match winning streak in all competitions, but their chances of extending that run past the coming week will be severely tested.
"The TV has the target to choose the matches Friday, Sunday, Monday. We want to continue doing our way with different possibilities tactically and with the players - but with a lot of matches, we can't do that".
Arsenal should make Aaron Ramsey captain and do everything they can to keep him at the club, according to former Gunners midfielder Jack Wilshere.
Arsenal have rescinded their offer of a new deal, meaning Ramsey could leave on a free transfer next summer when his contract expires.
With Manchester United, Juventus, AC Milan all linked with shock moves with the Wales worldwide, former playmaker Paul Merson, now a pundit feels it would be a "typical Arsenal" move to allow a player of his magnitude departs without compensation. "Individual things are not for me to speak about now". On Monday it's the same if he starts in the first XI or on the bench, to come with the focus for this match to help us.
"The same with Mesut as any other player. And all the people working there they said to us, this is the player [who has] the quality to play at PSG", Emery said.
Emery said the only new injury concern from the global break is a small knock picked up by Sokratis Papastathopoulos, who could miss the Leicester match. He is starting this week to do some training with us together and it is very, very good news for us.