Arsenal have reportedly opened talks over a possible deal to bring Brentford goalkeeper David Raya to the club.
Martinez impressed when standing in for Bernd Leno last season but did not receive first-team assurances from manager Mikel Arteta and was left out of the squad for their Premier League opener against Fulham this afternoon.
Arteta is understood to want a back-up sorted before allowing Martinez to leave, though, and 90min reports that they have now begun negotiations to sign Raya.
However, the Bees are reluctant to lose the 24-year-old, with manager Thomas Frank yesterday claiming that he is not for sale.
Raya kept 16 clean sheets last season as Brentford reached the playoff final.