During the regular season the Saints (and probably most all other teams) typically bring in several free agents for tryouts on Tuesdays, Saints players in season normal off day.
What's different about today is that this is the only player brought in for a tryout that has been disclosed so far. Players were off over the weekend. They may not have the traditional Tuesday off tomorrow. This could be just an evaluation of a player to consider for the practice squad. Maybe there's more to it than that.