Samir Carruthers has admitted that he was delighted to see the announcement that his transfer to United had been completed.
The 23-year-old midfielder, who signed a three-and-a-half year Blades contract after an undisclosed fee with MK Dons was agreed, waited patiently for the formalities to be finalised.
"I completed the medical on Monday and signed my paperwork, it was then just a case of waiting," said Samir. "I was like a kid waiting to see the announcement, refreshing my phone until it was done on Tuesday morning.
"I'm buzzing, I can't wait to get started with the lads. I don't know any of the lads but I'm sure they will be a welcoming bunch from what the manager has told me.
"Chris Wilder seems like a great bloke and I'm really looking forward to working with him and the coaching team."
Samir, who played for Aston Villa earlier in his career, is keen to make his S2 bow, adding: "I've played at Bramall Lane a couple of times and the atmosphere is unreal. I've won and lost but what has always struck me is the passionate fans, I've got no doubt that it is going to be a special place to play."