Macbook Pro 2011 SSD Placement Location
There will be no problem.  A SATA SSD has the same connectors as a SATA HDD drive so the connectors are identical.




To use you SSD in the optical bay, a optical bay drive kit is required.  You simply need to remove the SSD from the kit and replace it with the HDD into the same optical bay kit.

To answer your question...


  Does it even matter?


Nope.  It makes no difference.