The Blades face the Tigers in the semi-finals of the competition on Sunday, having already knocked out Aston Villa and Fulham on their run to the last four.
United's last Wembley visit ended in penalty-shootout heartbreak in the League One playoff showdown against Huddersfield Town in 2012, which Porter has described as the worst moment of his career.
The 30-year-old has admitted that the contingent of the United squad that were playing on that day are determined to put those memories behind them by completing their unlikely run to the FA Cup final.
"It was a nightmare," he told reporters. "I think that's probably the worst way to lose one. Especially after they missed their first three penalties, I thought we were on our way.
"I was taking the fifth penalty and thought I was going to have the chance to score the winning penalty, but it wasn't to be. The dressing room after was as bad as anything I've ever seen. We were devastated.
"A lot of the lads who played in that are still here," he added. "There are probably five or six players and the experience from that can only benefit us."