Barrett was assistant to manager Mark Stimson at Stevenage when they won the first trophy at the new national stadium by beating Kidderminster in the FA Trophy two years ago, and he is hoping for more glory against Shrewsbury on Saturday.
"I remember the look on the faces of the opposition when we played Kidderminster," he told KentOnline. "They were desolate at the final whistle and it's a horrible place to be when you've lost.
"We were lucky to win there at Stevenage and we had a great day and we're hoping that this day matches it.
"We just have to keep focusing on the positives and encourage everyone to be optimistic.
"We need to make sure we aren't overawed by the occasion and try and keep the lads' feet on the ground and instil into them that it's just another game of football, and one we're desperate to win to achieve the goal which we set out for at the start of the season, which was promotion."