Junior Pete Thomas played 39 snaps, completing 6-of-15 passes for 100 yards with an interception while rushing for -6 yards on four carries.
Mitchell tossed an 80-yard touchdown pass to Quinton Payton that gave NC State a 20-17 lead with 6:37 remaining, but after Duke scored to take a 24-17 lead both quarterbacks would throw three interceptions, two that were returned for touchdowns.
"The performance in the last however many minutes it was at quarterback hurt us," said Doeren. "One of the plays that Duke made was a phenomenal play. Brandon saw a guy open in the flat and their guy jumped up and tipped it to himself. It was a tremendous play. I don't fault Brandon for throwing it in the flat to David [Grinnage] there. He was wide open.
"But the other throw that he made was behind, and the throw Pete made was into coverage. Those are the kinds of plays that... we have to obviously find a way to not injure ourselves with turnovers in the fourth quarter. That's the key. As coaches, it's our job to get guys into position to make plays and to do everything we can to help them execute those plays."
Doeren added that the plan is to face Boston College without the rotating at the position that took place in Durham.
"Brandon is going to start this week and he'll play," said Doeren. "It will be his game. Whether Pete plays or not, we'll see, but we're going to go back to that formula. When it's not working, we're going to work every angle that we can.
"We rode with one of them and then he got hurt, and then we rode with another one. Then we rode with Brandon and Pete came in and gave us a little juice in a game so last week we thought rotating the two guys would be good. It didn't work."
The problem is the Pack hasn't been able to make the plays in the final quarter to win games. NC State has either led or trailed by a touchdown in the fourth quarter in five of the six losses this season.
Often those games are won by plays made at the quarterback position.
"If you look at all those losses... quarterbacks win games for teams in the fourth quarter in tight games a lot," said Doeren. "I know those kids want to do that. We're going to continue to try to help them and do everything we can from a play-calling standpoint to give them the best call that we can in those situations.
"Both of those guys are great kids. For most of the game they are doing what they are asked to do."