The 24-year-old rose through the Torino youth ranks before being promoted to the senior squad in 2018, making his debut at the age of 18 a couple of months after signing his first professional deal.
Buongiorno has since blossomed into an integral player for the Turin outfit, playing 92 matches across all competitions and racking up three goals and five assists in the process.
The defender came up with one goal and two assists in 34 Serie A matches last season, even captaining his club on eight occasions as Torino finished 10th in the standings.
This season, Buongiorno has again demonstrated his importance to Ivan Juric's mid-table side with two goals and an assist in 14 games, although his campaign has been partly hampered by an adductor injury.
The Italian - who cuts an imposing figure at 6ft 3in tall - made his senior Italy debut in June's Nations League third-placed playoff win over the Netherlands, before earning his second cap in a 0-0 draw with Ukraine in Euro 2024 qualifying last month, and he is expected to earn a spot in their squad for next summer's tournament.
To reflect his growing importance to the team, Torino handed Buongiorno a new-and-improved contract before the start of the 2023-24 season, and his current deal does not run out until 2028.
Nevertheless, The Sun reports that Chelsea have been alerted to the 24-year-old's progress in Turin, and the club's scouting division will be keeping a close eye on him over the Christmas period.
The Blues have apparently taken a liking to Buongiorno's abilities on the ball, as well as his versatility, as he is also comfortable on the left-hand side of the backline as well as playing centrally.
Chelsea are not the only club aiming to prise the Italy international away from his boyhood club, though, as Serie A giants Roma, Inter Milan and Juventus are also said to be in the running.
Given Buongiorno's recent extension, Torino are said to have slapped a £35m asking price on the defender's head and have already rejected an offer of £21.5m from an unnamed Italian side, as they are confident that a Premier League club will pay more.
Despite the appointment of Mauricio Pochettino and another influx of summer arrivals, Chelsea are still leaving a lot to be desired on the pitch and are languishing in 12th in the Premier League table after 16 games.
As a result, the West London giants are supposedly hoping to bring in at least three new players in the January window, although their activity may be restricted by Financial Fair Play regulations.
In order to comply with FFP rules, Chelsea could try to offload out-of-favour duo Trevoh Chalobah and Malang Sarr - neither of whom have played a competitive game this season - although the former has been sidelined with a thigh injury.
The Blues must also plan for life without Thiago Silva, who turns 40 next year and will enter the final six months of his Chelsea contract in January.