Nigel Clough admitted tiredness contributed to a below par performance against Tranmere Rovers at Prenton Park on Easter Monday.
Looking back on the goalless draw on the Wirral, which ended United's hopes of a top six finish, the Blades boss remarked:
"We have put so much into our performances in the last two or three months and it was always going to take its toll, but we are pleased with a point and delighted with another clean sheet.
"We have to start looking ahead to next season, when you come to places like this you try to win the game, but if you can't win it is important not to lose.
"We were leggy in training on Sunday, having worked very hard on Friday to beat Stevenage on the back of the disappointment at Wembley.
"We needed some fresh legs and we were delighted to get young Connor (Dimaio) his first 90 minutes of professional football."
Clough continued: "We were poor in the first-half, Tranmere bossed the game, we had a good chance from a corner, but created little in open play.
"We improved in the second-half and could have won the game, but we just looked so tired and that was evident late on when Jamie Murphy couldn't get the ball out of his feet when he had a chance to win the match.
"Harry Maguire came off with cramp in both legs, so we have to rest the lads up ready for Port Vale on Friday."