Speaking to the official Huddersfield Town website, Jackson was disapointed with his players "I am bitterly disappointed because we deserved to go out of the Cup tonight. Mansfield came here and played well and we were poor. We were second best all over and deserved to go out of the competition.
"In the three years I have been back at the Club the players have probably let me down five or six times and this evening was the seventh. I'm just bitterly disappointed with the performance and the result.
"I try to protect my players and I can't tonight after that and it will take a much better performance to beat Nottingham Forest on Saturday. The players have always bounced back and they must after this.
"Full credit to Mansfield because it was not a fluke result. If someone had come here and witnessed that they would have said that Mansfield deserved to go through and rightly so.
"The players are down, the supporters are down, but there is no bigger and better game to bounce back at than Forest. There will be a big crowd and I still have faith in my players. I never doubt them, but I cannot defend them this evening.
"Colin Calderwood was here tonight, but I went to see Forest last night and he is probably thinking exactly the same as I did last night.
"I had complaints about the second goal, but you cannot blame the result on that. I was disappointed because he was offside and you can ask virtually any manager and none of them know the interpretation of that rule.