Betis land Italian
By Alex Livie
Last Updated: 01/01/70 1:00am
The 25-year-old, who spent the end of last season on loan at Brescia, was allowed to move on after Torino deemed him surplus to requirements.
Brescia decided against taking up the option on a permanent transfer and this allowed Betis to enter the race.
A deal was swiftly concluded and the player was unveiled on Tuesday after passing a medical with the Seville club.
Castellini has signed a five-year deal and his capture brings an end to coach Lorenzo Serra Ferrer's search for a commanding defender.