Mendenhall wound up with 100 yards on 17 carries, rather than the 99 he actually gained.
Tomlin said the Steelers benefited, but he added that the spotting of the ball is always tricky, even if it shouldn't have been in this situation. CBS cameras clearly showed Mendenhall coming up short on the play.
"They spotted it as a first down, and, in that situation, it worked in our favor so we moved on," Tomlin said. "I did think he was a yard short."
Mendenhall is seventh in the NFL with 1,173 rushing yards. He averages 83.8 yards per game.
Copyright 2010 by The Associated Press