ESSENDON defender James Stewart will miss at least two months after scans revealed a serious hamstring injury stemming from Saturday night's loss to Geelong.
The Bombers had initially hoped the 27-year-old had escaped with hamstring tightness before further assessment revealed a more severe setback.
It is a blow for the club's new-look backline with the 195cm Stewart earmarked to play a key role in defence this year after previously spending most of his time at Tullamarine in attack.
With Cale Hooker moving forward and Michael Hurley sidelined indefinitely, it is likely to open the door for young defender Brandon Zerk-Thatcher to fill a void in defence.
Zerk-Thatcher was an emergency for Saturday night's AAMI Community Series clash against the Cats.
Patrick Ambrose is currently working back from a foot injury and will present another option when fully fit, while top-10 pick Zach Reid continues his development.
Forward-turned-defender Jayden Laverde can play tall in defence, while the Bombers have moved skipper Dyson Heppell and Ned Cahill back in the shake-up under full-time coach Ben Rutten.
Recruit Nick Hind will also play an important role at half-back with the ex-Saint cleared of shoulder damage after a heavy hit against the Cats.
