Replaced Chopper - Is Pump OK?

I replaced a broken chopper assembly (the victim of a small pit), but want to verify that the pump is OK before putting it all back together. It seems to turn with resistance and makes a bit of plastic-on-plastic rubbing noise, but I can’t tell if the resistance is from the impeller or just back-winding the motor.

Before repairing the chopper, it seemed to drain fine (indicating that the pump/motor was working), but it also sprayed food particles all over the top shelf. Any tips for checking the pump? Thanks in advance.