Due to stretch and engagement running force with freewheel, inner link touches sprocket teeth. Thus, the inner link wears out. Usually there is no wear on outer links.
For high end chain, pins are riveted with capping to sustain more sideways force during gear change. For this type of chain, pin can not be reused. To reconnecting chain, special pin with guide or special quick connecting link designated by chain makers has to be used.
For a regular non-capping riveted chain where reusing pin is not prohibited, after applying the lubricant, using the chain tool to reconnect the chain, bent the chain sideways back and forth for few times to make sure that there is no tight link at this connecting point.