ORLANDO — The two Celtics losses before Friday’s impressive 108-100 victory over Oklahoma City are reminders that even the most experienced and savvy teams require reinforcements.

The Celtics were apparently losing themselves and losing direction after losses to the Pistons and Spurs. And after just 12 games, nearly 15 percent of the season, the Celtics were confused about the necessities in Doc Rivers’s system, especially on defense.