Battling a rib injury that limited him in practice all week, Mayfield struggled Sunday, throwing a pick-six on Cleveland's third offensive snap, setting the tone for the Pittsburgh rout.
Taking multiple big shots from the Steelers, Mayfield was especially inefficient on third down and while facing the blitz. On third downs, he went just 2-of-7 passing for 5 yards with a sack and two picks; when facing the blitz, Mayfield completed 2 of 6 passes for only 11 yards with an interception and three sacks.
Stefanski finally replaced Mayfield late in the third quarter with backup Case Keenum, but attributed the move to the 24-point deficit and to Mayfield's ailing ribs.
"I didn't want to see him get hit one more time," said Stefanski, who shouldered much of the blame for Mayfield's ineffective performance. "I know this, I didn't do a good enough job allowing him to be put in [successful] positions. I have to do way better. I can't let him get hit like that."
"Obviously, not good enough," said Mayfield, when asked how he played in Pittsburgh. "I've got to take care of the ball."
The Steelers pressured (a sack or creating duress) Mayfield on 52% of his dropbacks, the highest rate of his pro career, according to ESPN Stats & Info.
Stefanski reiterated that Mayfield would start next Sunday at Cincinnati, provided his ribs allow him to do so.
"As long as he's healthy," Stefanski said, "and I think he will be."