Turnover issues again temporarily cost him his starting job in 1989. DeBerg threw eight interceptions in the team's first three games, including five in one game (against the San Diego Chargers) on September 24. After sitting for two weeks, he briefly returned to the playing field; he then sat for two more weeks before finishing the season by starting the team's final six games. Among DeBerg's highlights was a 338-yard, one-touchdown, two-interception performance against the Pittsburgh Steelers in a 23–17 loss on October 29. He finished the 1989 season with 2,529 yards passing, completing 196 of 324 passes (a 60.5-percent completion rate), with 11 touchdowns against 16 interceptions.