After the 55-31 rout, in which the Steelers gave up 55 points and 610 yards (both franchise records), Tomlin said he was angry and disappointed in the way his team played.
The defense, which ranked in the top five in the NFL for six straight years from 2007 to 2012, is ranked 13th in total defense and 31st in rushing defense this season.
"You re-evaluate everything," Tomlin said to the Pittsburgh Post-Gazette. "You have to after a performance like that and we will. It doesn't necessarily mean we will change or change for the sake of changing, but we will look at every aspect of what we are doing and who we are doing it with because we can't have performances like that."
In the final 17 minutes of the game against the Patriots, the defense gave up 31 points.
"Those people who are lacking effort won't be playing," Tomlin said. "It's just that simple. ... I am angry, disappointed."