The Gunners have received a major boost in their pursuit of the Ivory Coast defender, who has attracted interest from a number of clubs in Europe.
Newcastle United, Liverpool, Chelsea and Arsenal have all watched the defender as they consider their options in the summer transfer window.
Diomande is considered one of the best young defenders in Europe and his rise at such a young age has furthered elevated his status in the game.
The Blues are looking to bring in a replacement of Thiago Silva, who is set to leave the club at the end of the season.
The Blues are looking to bring in a replacement of Thiago Silva, who is set to leave the club at the end of the season.
In order to replace the Brazilian, Chelsea have earmarked Diomande as their top target.
Not only Silva but also Trevoh Chalobah is likely to leave the club at the end of the season, which would force Chelsea to step into the market for a new central defender.
The defender has a £69m release clause in his contract and the Portuguese club are not willing to accept anything less than that.
Premier League leaders Arsenal have moved ahead of Chelsea in the race to sign the defender, who prefers to play for the North London club.
Arsenal manager Mikel Arteta is actively looking to make his squad even more stronger and he will consider signing a new centre-back this summer.
In order to provide competition to Gabriel Magalhaes and William Saliba and add cover for them, the Spaniard can make a move for Diomande.
The 20-year-old defender has contributed to yet another impressive season for Sporting, having helped the team to climb to the top of the league ahead of rivals Benfica.
The young defender has made 32 appearances for the team and played a crucial role in the title race this season.
