The 29-year-old has been long linked with a return to Santos, but Mattos is prepared to break the bank for the Brazilian forward.
"We had talks about 15 days ago and I made it clear that, for Robinho, Cruzeiro will not spare any effort to sign a big-name player like him," Mattos told Radio Itatiaia.
"We want Robinho. Cruzeiro has even talked about values with him. He made it clear that Santos are his priority since they sold Neymar.
"That's what he wants. But I made it clear the doors are open and that Cruzeiro will not spare any effort."
Robinho left Santos to join Real Madrid in 2005.