Do you mean the "roller" that hangs out on either side? This is the part that the dogs on the back of the trigger guard/action lever ride against to pull the locking bolts back out of the frame.
Or do you mean the pin that holds the locking bolts in the lug? I would think that if this were missing the bolts would not stay in the barrel, so I'm assuming you mean the roller.
Call TC and they'll send you one. It's easy to replace, just drive out the pin, put in in place and put pin back in.
