That's probably what he's doing, which is understandable. But at this stage in his career I dont think taking tuneups is a great idea.
Martirosyan would be a good fight. Yeah he struggled with Kassim, but he has an unbelievable chin and his pressure style can cause problems. Though it has to be said it doesn't bode well for him against Cotto's boxer/pressure style. It's possible Martirosyan is not the prospect people thought but he could well be better than that fight suggests, and is clearly a better option than Bundrage, Wolak and Alvarez I've not actually seen.
Plus you've gotta give Vanes a bit of credit for beating Joe Greene, an undefeated prospect much like himself. He's not great but its not much different to Pirog beating the untested Daniel Jacobs.