With Antonio Amaya also sidelined through injury, Ustaritz is expected to partner Chechu Dorado in defence.
Meanwhile, young playmaker Alejandro Pozuelo has recovered from injury and could start for the Verdiblancos.
Sevilla coach Marcelino Garcia Toral will be without Frederic Kanoute, who serves a one-match suspension for accumulating five yellow cards. Argentine midfielder Diego Perotti sits out with a hamstring injury.
Manu del Moral (hamstring) and Martin Caceres (flu) are both doubtful to feature, but the former will find a spot in the starting XI if he is passed fit.
Real Betis, who are 11th in the league standings, go into Saturday's clash just four places and three points behind their bitter rivals. The Verdiblancos are on a three-game winning streak at the Benito Villamarin.The Andalusian club's 4-2 defeat at Barcelona last Sunday made them the first away side to score at Camp Nou this season.Sevilla ended a three-game losing streak in the league with a goalless draw at home to Espanyol on Saturday.The Rojiblancos have won just once on the road this season (W1 D5 L2). Frederic Kanoute is Sevilla's top scorer this season with six goals..
