Essendon's mounting injury worries show no signs of abating with emerging midfielder Matt Guelfi's season over after hurting his knee at training on Monday and rebounding defender Adam Saad sidelined with a hamstring injury.

However there is some good news at the Bombers, with highly rated assistant coach Blake Caracella set to return to the club next year after parting ways with Richmond.

Essendon's Matt Guelfi has suffered what is believed to be a serious knee injury. Credit:AAP

West Australian Guelfi left the track on Monday with a knee injury, with the club confirming on Tuesday that he had torn his meniscus and needed season-ending surgery.

It is a further blow for Essendon, given Guelfi has been a regular this year, playing 17 games in his second season since arriving at Tullamarine as a mature-age draftee.