I generally don't worry for MLB, NFL, and the NBA on what the team's record is in until about the middle of the season unless they drop say their first 4-5 games in the NFL. I don't count college football where if you lose one game, you are more or less toast for the championship (which is why we need playoffs).
I know some though who think that if you are at or slightly below .500 come the middle of the season you don't have a prayer, even though the other team is only say 6-7 games ahead in the standings.