Chicago Bears tight end Zach Miller had emergency surgery in order to save the left leg he injured on Sunday night.

The surgery was aimed at repairing an artery in Miller’s leg, and required grafting tissue be removed from Miller’s right leg in order to repair the damage to the artery, according to ESPN. The procedure was performed in New Orleans by vascular surgeons after the Bears’ 20-12 loss to the Saints.

Officially the injury was ruled as a dislocated knee, but sources told ESPN that the problem was ‘more significant’ than a regular dislocation.