Ollie Norwood echoed the sentiments of boss Chris Wilder, following Tuesday draw with Stoke City at Bramall Lane.
The Northern Ireland international felt the Blades did more than enough to overcome Gary Rowett's Potters, something that looked on the cards until Joe Allen's equaliser against the run of play with just a few minutes remaining.
Norwood remarked: "We definitely deserved more than a point, we dominated the whole game really.
"It was a tough one to take and for the second game running we've come off feeling a bit deflated and really frustrated.
"We should have been two or three in front by the break at Derby, we weren't and then dropped off in the second-half and got punished."
The experienced midfielder added: "We should have been well in front again by half-time, so we've got to be more ruthless and put these teams to bed when we have the chance to.
"They had a lot of quality, but we matched them and bettered them in all areas, that's what's most frustrating."