Everton have won just two of their first nine league matches, while they also sit bottom of their Europa League group.
Unsworth, who is in charge of Everton's Under-23s, played the best past of 11 years at Goodison Park across two spells and has been linked to the club in a coaching capacity since 2013.
Everton can confirm David Unsworth will take temporary charge of the Everton first team, commencing with tomorrow night's @Carabao_Cup tie. pic.twitter.com/vyiEXZDZvI — Everton (@Everton) October 24, 2017
He will likely be hoping to stake his claim for taking the role permanently, but Burnley manager Sean Dyche is reportedly considered the favourite.