Coutinho sealed a permanent switch to Villa from Barcelona in the close season following a successful loan spell but the playmaker has not scored or provided an assist in 12 league matches.
He was absent from Sunday's 3-1 Premier League victory over Manchester United and will miss Thursday's trip to Old Trafford to face United again in the League Cup and Sunday's visit to Brighton & Hove Albion in the league.
Emery confirmed Coutinho was sidelined due to a quad issue.
"I don't know how long it'll be but, today (Sunday), he couldn't play and he's not going to play until after the (World Cup) break," he told the Birmingham Mail.
"He's not going to play on Thursday or Sunday because he's injured and he's out longer."
Brazil head coach Tite is set to announce his 26-man squad for the November 20th to December 18th World Cup in Qatar later on Monday.
Coutinho made his debut for Brazil in 2010 and has earned more than 60 caps but his disappointing form this season has led to doubts about his place in the squad.
