connecting clawfoot tub to existing drain line in concrete basement
 

We are trying to replace the shower in my basement bathroom with a clawfoot tub. So far, I have removed the old shower and drain. I will be having a plumber come to reroute and connect supply lines for the tub and also to connect the drain.

The bathroom is in the basement. It has a concrete floor. Coming out of the floor is a 2" cast-iron pipe (which the shower drain was previously attached to). It extends 1" above the floor and is unthreaded. I have measured and this drain should not need to be moved to accommodate the tub.

My question is: Should my plumber be able to connect the tub drain to this pipe (using some appropriate adaptor)? Or, am I going to have to jackhammer out concrete to expose the rest of this pipe and the p-trap it presumably connects to?

Thanks for your help.