Toshiba will power Project Ara, so says Japan's largest business daily.
The Japanese electronics company will supply three types of processors that will control, among other things, the flow of data and electrical signals between the modules and the phone, the Nikkei report said.
The electronics maker is the only Japanese company to become a "preferred supplier," according to the report.
Sample shipments of the silicon will start this fall, with mass production to begin early next year.
The Google phone will have components that fit together like Lego blocks, as seen in a Google video.
The phone, which will have between 5 and 10 modules, can be customized based on need. For example, swapping in a second battery if extra battery life is needed or adding a particular kind of camera module.
Interestingly, the report says the "least expensive handset in Google's new line will be priced at around $50," and Nikkei projects demand to be in the tens of millions of units in the first year of sales.