Mawae was fined $5,000 for unnecessary roughness and Stewart was fined $12,500 for two unnecessary roughness penalties.
Both players made late blocks on Chargers' linebacker Shawne Merriman in San Diego's comeback 23-17 victory in overtime.
The late blocks came during separate pass plays.
Neither player was penalized, but the all-pro suffered a sprained knee and will not play Sunday against the Detroit Lions.
"The game is a violent game and I understand guys can get hurt playing this game," Mawae told the Tennesseean earlier this week. "I understand Merriman thinks I took a cheap shot on him (but) I would never intentionally try to hurt somebody."
Also, Chargers' linebacker Shaun Phillips was fined $7,500 for a horse-collar tackle on Titans running back Chris Brown.
Phillips was not penalized.