Collins revealed that his character Castiel will be reluctant to aid the Winchesters in their fight against the Leviathans.
"It comes down to one final confrontation with Dick Roman (James Patrick Stuart)," said the actor. "The only problem is - from my character's perspective - it's difficult for me to really be of substantial assistance in this project."
Fallen angel Castiel returned to life in a recent episode, but was left confused and disoriented by the experience.
"Castiel is not only now crazy but he's also a pacifist," explained Collins. "[He's] completely and totally unwilling to participate in any kind of fighting or aggressive activity."
Supernatural was recently renewed for an eighth season, to premiere in the fall on The CW. The current season concludes this Friday at 9/8c.
Watch Misha Collins discuss the Supernatural finale below: