The Daily Express says Emery is looking to make a move for a central defender this summer.
And the Spaniard has set his sights on Hermoso, formerly of Real Madrid, it has been claimed.
Journalist Alex Perez, of Radio Marca, believes the Gunners are looking to raid for the 23-year-old as they look to bolster their backline.
He tweeted: “Mario Hermoso's name sounds strong in London. The Arsenal is one of the teams interested in the center #RCDE".
Any move could be dependent on Real, however, which boast a buy-back option for Hermoso.