Cardiff have a pre-contract with the Real Valladolid striker, but face missing out on the 32 year-old should they be relegated.
Sport says Espanyol will step in and snap up Guerra if Cardiff fail to beat the drop.
He said: "Cardiff are still interested, but I have not signed anything with anyone.
"There are teams interested, but they have to wait until the summer.
"I am now focused on saving Valladolid."