NORTH Melbourne will almost certainly face the marking power of Essendon's forward line on Saturday night without its two first-choice key defenders.

Lachlan Hansen has been groomed by North to settle at centre half-back in 2012 but will miss round one with a minor hamstring injury. And full-back Nathan Grima is an unlikely starter against the Bombers, having not played since injuring his right knee in round one of the NAB Cup.

Hansen strained his hamstring in Werribee's win over North's other VFL affiliate, North Ballarat, on Saturday, and did not return after half-time. But North says the injury is minor and he may only miss one week.

Grima was strongly considered to make his return in that same match, having made a speedy recovery from a high-grade medial ligament tear. But when he did not take his place in Werribee's team his ambitions of playing the first round one game of his AFL career took a dive. Given he has not played since February 17, it is extremely unlikely North will bring him straight back in against the Bombers.

Pick your BEST 22 to take on the Bombers

Not being able to call on your full-back and centre half-back is never ideal, but the timing of Hansen and Grima's injuries is particularly bad for North as it prepares to take on Essendon's emerging key forward Michael Hurley and fellow talls Patrick Ryder and David Hille.

Hurley was outstanding in the Bombers' only encounter with North last year, kicking four goals and taking seven marks in the Bombers' 21-point loss.

Fortunately, North has enviable depth in its key-position stocks and can call on one, or both, of Luke Delaney and Cameron Pederson this Saturday night. Both performed strongly in the VFL on the weekend, but specialist defender Delaney is probably the frontrunner for selection over utility Pedersen.

If North selects only one of the duo, either Scott Thompson or Michael Firrito will have to concede height and weight to a Bomber tall.

Robbie Tarrant also has experience as a key defender, but North seems committed to playing him in attack this season.

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