Ljungberg - who played 325 games for the Gunners between 1998 and 2007, winning two Premier League titles and three FA Cups - moved up from the under-23s to become Emery's assistant this summer, with Steve Bould going the other way.
Arsenal will hope that the appointment will help some of the club's younger talents ease into the first-team setup, and speaking after the 2-1 win over Bayern Munich in Los Angeles on Wednesday , Emery hailed the Swede's knowledge of the players.
“He knows better than us every young player," he said.
"For example Robbie (Burton), I didn't know. Freddie said to me he's a good player to play more like a 6 or 8. Really he helped us."
The Gravesend-born youngster picked up five goals and four assists for the Gunners' under-18s last season, his first campaign since going professional.