Doncaster Rovers were much hungrier than Sheffield United admits apologetic Speed

The Blades lost 2-0 in the South Yorkshire derby at the Keepmoat Stadium with the club's former striker Billy Sharp bagging one of the goals.

The result leaves the Blades four points above the Championship relegation zone while victory lifted Rovers to within two points of the top six.

Speed, who watched the game from the stands due to a touchline ban, said: "I have to apologise to the fans because the first-half performance was unacceptable.

"We were not at it and, for whatever reason, Doncaster wanted it more than us and were hungrier.

"It's a worry because I have never, ever questioned the boys' work-rate and commitment. We are giving teams starts and finding it difficult to come back."

Since his appointment as manager 11 games ago, the Blades have picked up 14 points from a possible 33. Significantly, they have yet to win back-to-back games.

"I was very confident coming into this game because our last two results against Burnley and Hull were very positive," he added. "But the players have to recognise that, if we are not playing well in possession, we have to make up for it in other areas."

Speed cited Queens Park Rangers, who are managed by former Blades manager Neil Warnock, as an example to follow.

"We need to be more ruthless. Look at QPR (against Bristol City) on Friday night. They didn't play great but they made up for it in other areas. They ground a result out and that's why they are top of the league. That's what we have to learn."

Former Blades striker Sharp suffered a hamstring injury after scoring his goal and scans today will determine the length of his absence.

Sharp, a lifelong Blades supporter, refused to celebrate his goal but wore a T-shirt underneath his shirt sporting the phrase "Fat Lad from Sheffield."

Manager Sean O'Driscoll had used the phrase during preparations for the game and said: "Billy gets really frustrated when he has chances and misses and, last season, they all went in so we never saw that other side of him.

"This season he has got a little bit frustrated and we have lost that edge that he had to his game. When he plays like he can do, he is strong, muscular, and bullish and gives defenders problems. When he doesn't, he is just a fat lad from Sheffield!"

"It was meant in a half-hearted way," he stressed. " But, unbeknown to me, he has put that on the back of his shirt – especially for the TV cameras, as well. So maybe he has got his own back on me."

Rovers striker James Hayter suffered a cut mouth during the game as a result of a loose elbow from Blades captain Chris Morgan.

Speed dismissed the incident afterwards saying: "'I watched the incident on the box. It was nothing. I don't think Morgs even knew he was there. I also saw the 'penalty' we should have had on the replay as well. But we don't get penalties. We have not had a penalty at home for 14 or 15 months."

The Blades are hoping to reach agreement with Manchester United this week to extend the loan stay of defender Ritchie de Laet.