Storage ( SATA DRIVE install ) uninitialized

Hello,

I have added some additional SATA 3.5 internal harddrive storage (via promise pegasus) to my MacPro.

Cables are properly seated.

Upon booting up, I receive:

"The disk you inserted was not readable by this computer."

I ran the Disk Utility>First Aid, but it is still uninitialized.

I should have inquired what I needed to do at MicroCenter, but I'd just want to confirm the next step.

Do I reformat this new hard drive ?

Any input in appreciated,

J.