Merge Inventory - Same item, slightly different SKU

Merge Inventory - Same item, slightly different SKU

I have an issue and not sure how to solve.
I have multiple selling platforms. I use Zoho just for inventory control.
On certain sites I have had to add a digit to the SKU, so for example the SKU is R2000 and on certain sites its R2000a. Can I link / merge these together under inventory items to ensure it tracks and adjusts correctly.
Thank you.