Per twitter..
The Diamondbacks and Jose Valverde have agreed to terms on a minor league deal, according to Jon Heyman of CBS Sports (on Twitter). Valverde is a client of the Boras Corporation.
With this deal, the 36-year-old Valverde returns to the organization that signed him as an international free agent in 1997. "Papa Grande" spent the first five seasons of his career with the Diamondbacks (2003-07), leading the National League with 47 saves in his final season there. He was then traded to the Astros for Chris Burke, J.C. Gutierrez and Chad Qualls that offseason.
With Addison, Valverde, Putz, Hernadez and Ziegler, it looks like Closers is far from certain at this point.
10:25am: Valverde told Enrique Rojas of ESPN Deportes that he does not have a deal with the Diamondbacks and has recently switched agents. Formerly with Scott Boras, he is now represented by Praver/Shapiro (Spanish Twitter links).