This can be done and will appear as a Pay-Gift-in-Kind once the gift is applied to a pledge. This can be done in one of the following methods:

Adding Gift on the Constituent Record
  1. Open a Constituent record and navigate to the Gift Tab
  2. Add "New Gift"
  3. When prompted to apply gift to a pledge, select Yes
  4. Select which pledge you would like to apply the gift to
  5. Add gift information and make sure the Gift Type is set to Gift-in-Kind
  6. Save and close gift
* If you don't select Yes when prompted to apply for a pledge, after entering the gift information, you can go to Gift > Apply to > Pledge and select the pledge from there.

Apply Existing Gift-in-Kind gift to an Existing Pledge
  1. Open Gift-in-Kind record from a Constituent's Gift tab
  2. Go to Gift > Apply to > Pledge 
  3. Select which pledge you would like to apply the gift to
  4. Click OK and then Save and Close
* This will only work if the gift has not been posted.