"I didn't feel in my gut that, going the way we were going, that it was going to change and it was going to get better.
This marks the second time Harbaugh has fired an offensive coordinator during the season; in 2012, he dismissed Cam Cameron, a move that helped propelled Baltimore to the Super Bowl.
"We're not putting enough points on the board, and we're not putting enough yards on the board for the amount of times we're throwing the ball," Harbaugh said.
"We're in good position to have a guy with that kind of experience here and experience in this west-coast terminology," Harbaugh said.
But the basic system is not going to change."