Jim and John Harbaugh have exchanged a handful of text messages, and plan to leave it at that. No phone conversations necessary while the season’s still going. No time for pleasantries, even for the friendly siblings.

There is work to be done to prepare for the Super Bowl, prepare for each other, prepare for a history-making day already being widely hyped as ‘‘Harbowl’’ or ‘‘Superbaugh’’ depending which nickname you prefer.