Charlie Day (HORRIBLE BOSSES) is in negotiations to board Guillermo del Toro's PACIFIC RIM, reports Variety. The Legendary Pictures production already stars Charlie Hunnan (TV's SONS OF ANARCHY). Day would take the role of a professor in the alien invasion film.

Travis Beacham wrote the screenplay. Legendary's Thomas Tull and Jon Jashni are producing.

Filming is set to start in the fall.