Martinelli has cemented a regular starting place at Arsenal and has continued to impress this season under Mikel Arteta.
The 21-year-old has already scored three goals and provided one assist in nine games this term.
He has now managed 21 goals in 93 appearances for the Gunners since joining the club from Brazilian side Ituano in 2019.
Martinelli has started every single Premier League match for Arsenal this season and the winger’s performances have started to attract attention from other sides in the Premier League.
London rivals Chelsea one of several clubs currently monitoring Martinelli, according to the Daily Mail.
Martinelli is under contract with Arsenal until 2024 but the north London club are keen to tie him down to a new long-term deal.
In addition to Martinelli, Arsenal are also working on new contracts for Bukayo Saka and William Saliba, who has impressed for the Premier League leaders since returning from his loan spell at French club Marseille.
It is unlikely Arsenal would consider selling Martinelli to one of their main rivals in the Premier League.
But the club’s hand could be forced next summer if the Brazilian refuses to sign a new deal.
According to the report, Arsenal also intend to further strengthen their squad in the January transfer window.
A new central midfielder is the top priority for Arsenal boss Arteta, who is said to be leaving “no stone unturned” in ensuring the club’s Premier League title challenge does not fade this season.
Arsenal are currently one point clear of defending champions Manchester City at the top of the table.
Arteta is expected to rest players against Bodo/Glimt in the Europa League on Thursday before the Gunners return to Premier League action against Liverpool at the Emirates on Sunday.