Anderson Machado is back in the US, and had knee surgery yesterday performed by Reds medical director Dr. Kremcheck.
Machado won't be available for months, and unless one of the other options at shortstop is injured at some point this season I'm not really sure how the Reds will be able to play him after acquiring Rich Aurilia.
More than likely something will happen to open up an opportunity for Machado (Felipe tanks, Aurilia gets traded, etc.), but if Lopez and Aurilia both play well then it'll be interesting to see what the Reds do when Anderson is healthy again. While he's not an uber-prospect, he's still not someone you want to waive, and the Reds might not have a choice since he's out of options.