Processing whole clove with the liquid sounds iffy -- can you tell me if I can sub in already ground clove and if so, how much?

The conversion rate is 1/4 tsp ground cloves for 3 whole cloves, so I'd use a generous 1/8 tsp ground cloves. You could also try sending the recipe author a direct message to ask their opinion. Just click the little envelope button on their profile page (http://food52.com/users/5488-pati-jinich).