Bennett has been ruled out for around six months having ruptured his anterior cruciate ligament in Tuesday's Capital One Cup defeat to Yeovil.
Midfielder Marc Laird hopes to be fit having sat out in midweek with a slight knock.
Winger Kevan Hurst (knee) has missed both Southend's matches at the start of the new season and will again be assessed.
- Sports & Recreation
- anterior cruciate ligament