PSG activated the release clause in Digne's contract earlier this month, and the 33-year-old France international underwent a medical with the Champions League holders two weeks ago, with his £8m move expected to be finalised once he returns from holiday.
That left Aston Villa needing a replacement, and the two clubs had broadly agreed a fee for Ruggeri in the region of €20m earlier in the week, with the 24-year-old now advancing through personal terms.
Ruggeri did not travel to South Korea for Atletico Madrid's pre-season tour as talks with Villa continued, a clear sign of how close the move has become.
Villa had initially pursued AC Milan's Pervis Estupiñán, a player who worked under Unai Emery at Villarreal, and personal terms were not seen as an obstacle in that deal.
It was AC Milan's asking price that proved the sticking point, complicated further by the Italian club's recent appointment of Ruben Amorim as head coach. Ruggeri instead emerged as the alternative, fitting the more physical profile Villa have been seeking at left-back, someone capable of offering greater balance than Ian Maatsen, who has struggled for minutes since joining in 2024 but remains part of Emery's plans as a long-term successor to Digne regardless.
At 6ft 2in, Ruggeri offers the physicality Villa are after, along with previous experience playing in central defence that adds further versatility to his profile. He made 47 appearances for Atlético last season after joining from Atalanta, recording seven assists and signing a five-year deal in Madrid.
With Alejandro Garnacho having joined to provide width on the left of Emery's attack, a more defensively-minded option at full-back would help offer greater balance to the side, even though Emery typically wants his left-backs to play high and wide.