Losing two straight to fall to 6-6 on the season, the Celtics allowed the Spurs to shoot 58.4 percent from the floor while also allowing 58 points to be scored in the paint.
"We just let a team shoot 58 percent against us. We let a team shoot 50 percent from the three against us," Rivers said on Wednesday. "And it's tough to win a game, you shouldn't win a game, if that happens."
The Celtics will be facing the No. 2 scoring offense in the NBA, as the Thunder average 103.0 points per game while shooting 48 percent from the floor. While Boston's defense has struggled this season much of the issue has been offensively as well, as the Celtics have scored just 97.2 points per game while allowing 99.3.
The Thunder tipoff against the Celtics at 6:30 p.m. CT.