Arsene Wenger is trailing Valencia defender Raul Albiol, 23, as he looks to launch a major shake-up of his defence this summer.
Arsenal also enquired Albiol's teammate Carlos Marchena in January.
Meanwhile, Salomon Kalou has admitted it would be a "dream" to play for Arsene Wenger and hinted that he might quit Stamford Bridge in the summer.
The Arsenal boss tried to sign the Chelsea forward last summer but a £6million bid was turned down.
"Arsene Wenger said he thought of signing me? That's an honour for me," Kalou told setanta.com.