The conn would have fallen either to Mr Worf, or to Mr Data. ...Lt. Data is 2nd officer... he would take over after Picard and Riker Lt. Cmdr Data, then Lt. Cmdr Laforge, and sadly enough of the the Common Bridge Crew, Troy is next in line. She has an honorary Rank of Lt. Cmdr. Dr. Beverly Crusher also holds the rank of Commander, and is authorised to command the bridge, but generally does not do so in favour of remaining in sickbay and allowing the designated command crew to take charge