Robinson's men fell behind very early on against the Championship Reds on Saturday and never fully recovered and their captain Lewington admitted that the less than ideal start made their already difficult task of making it into the last 8 of the Cup, even harder.
Speaking after the game, the 28-year-old said: “The first half was particularly poor especially with the first 25 minutes. They really caught us out and the first goal completely killed the mood.
“We couldn’t get going in the first 25 and we struggled, and Barnsley were worthy of their two-goal lead. It was very frustrating, the first goal just completely pricked the balloon and it was very hard to come back from that.
“There wasn’t too much finger pointing at half time, it was more positive. Karl is always trying to be constructive, we couldn’t change the first half but we could affect the second and so we changed a few players around and it had an effect.
“With the first half being so poor it was good in the second half that we came out and had a go because that’s the very least we should be doing.
“I thought our fans, after the goal went in, were fantastic, they were making a fantastic noise and in the end it makes a big difference.”
However, despite missing out on a place in the quarter-finals, the experienced full-back believes both the players and the supporters can look back on this season’s FA Cup campaign with fond memories.
“When you look back on it at the end of the season it’s been a great cup run and we’ve made some really good memories out of the cup and we’ve enjoyed it - it’s just a shame that it ended the way it did.”