The club confirmed the move in an official statement: "Bologna FC 1909 announces it has acquired on a permanent basis from Real Oviedo the sporting rights to defender Rahim Alhassane."
The deal makes Alhassane the first Nigerien player in the club's history.
Bologna's statement also offered a profile of their new arrival, describing him as "a modern left-back, blessed with pace, intensity and a strong attacking instinct."
Born in 2002, Alhassane completed his football education in Spain, where he rose through the ranks to establish himself at Real Oviedo. His performances in recent seasons earned him a permanent place among the club's professionals and a growing role with Niger's national team, of which he is now a key figure. His move to Bologna follows a season in which he made 27 appearances as the left-back in a back four.
Alhassane, who has 26 caps for Niger's senior side, has spent his entire career in Spain with smaller clubs. He moved to Recreativo Huelva in 2023 before joining Real Oviedo the following year, where his performances were strong enough to earn a call-up to Serie A with Bologna.
Tedesco will have to wait a little longer before he can call on his new full-back, however. Alhassane is due to fly back to Spain in the coming days to complete residency permit paperwork, since as a non-EU player without dual Spanish nationality, despite his years playing there, he must process the formalities through the Italian embassy in Spain.
The situation echoes that of Jonathan Rowe a year ago, who faced a similar delay following his move from Marseille.
The signing follows Bologna's earlier addition of Caccavo this summer, with the club continuing to build out Tedesco's squad ahead of the new season.
Alhassane's arrival gives the coach genuine depth at left-back for the first time since Miranda established himself as first choice, with the Nigerien expected to provide an attacking outlet down the flank once he completes the bureaucratic process and is available for selection.