Arsenal are about to launch a £70million bid to sign William Carvalho and Gelson Martins.
The Gunners have already made an official approach to sign the two players.
Preliminary talks have been held with Sporting Clube de Portugal and the two clubs are expected to meet again before the end of the week.
Arsenal have already secured the services of defender Sead Kolasinac and striker Alexandre Lacazette.
Manager Arsene Wenger is determined to build a title-winning squad ahead of next season.
The North Londoners endured a very disappointing campaign last season as they failed to finish in the Top Four.
But with no Champions League football, the Frenchman has made it clear that the Premier League will be his main objective for next season.
