Despite his tender age, Diomande is already a trusted member of Ruben Amorim's Sporting setup and enjoyed a breakthrough season in the 2022-23 campaign, scoring one goal in 17 games.
The former Midtjylland youngster was a regular during Sporting's run to the Europa League quarter-finals, and he played the full 120 minutes in their last-16 second leg win over Arsenal at the Emirates.
Since the start of the 2023-24 season, Diomande has established himself as a key fixture of Amorim's backline, and he has started all four of their Primeira Liga matches, setting up one goal.
Thanks to Diomande's efforts, Sporting have taken 10 points from their opening four matches to sit third in the embryonic rankings, only behind Porto and Boavista on goal difference.
The right-footed defender - who stands at 6ft 3in tall - earned his first Ivory Coast call-up for September's fixtures owing to his impressive displays in Portugal, and he made his debut in a 1-0 win over Lesotho on Saturday.
Diomande's exploits in the Primeira Liga have not gone unnoticed, and according to Portuguese outlet Record - via football.london - Arsenal made a move to sign him over the summer.
The Gunners reportedly came forward with an offer of €35m (£30m) for the 2003-born starlet, but their approach was knocked back by Sporting, who have him under contract until the summer of 2027.
Arsenal have apparently promised to try again for Diomande's signature next year, but the outlet adds that Sporting have set his release clause at a whopping €80m (£68.6m), and they have reminded the Gunners as such.
Arsenal allowed no fewer than three central defenders to leave the Emirates permanently over the summer, including Pablo Mari, whose loan to Monza became permanent when the Serie A side avoided relegation.
Meanwhile, Auston Trusty - who did not make a competitive appearance for the club - left for Sheffield United, while Rob Holding ended his seven-year association with the club to sign for Crystal Palace.
Gabriel Magalhaes's future was also plunged into doubt amid reports of interest from Saudi Arabia, and the Brazil international briefly fell out of favour under Mikel Arteta at the start of the season.
Gabriel was named on the bench for each of Arsenal's first three Premier League games, as Thomas Partey, Ben White and William Saliba made the first XI with Takehiro Tomiyasu, Jurrien Timber and Jakub Kiwior all taking up left-back roles.
However, Gabriel was brought back into the starting lineup for the Gunners' 3-1 win over Manchester United, as Arteta is currently without both of Partey and Timber due to injury.
The former Lille man suffered a scare of his own on his Brazil debut against Bolivia at the weekend, but he is understood to have trained normally with his teammates on Sunday.