John Egan has come along way since he made his made his United debut as a loanee at Walsall back in March 2012.
United's new club record signing has since made 81 league appearances for Gillingham and most importantly 67 in the Championship with Brentford of the last two seasons, also becoming skipper at Griffin Park.
But the 25-year-old is delighted to be back at the Lane, having put pen-to-paper on a four-year deal.
He commented: "It's been a long time since I was first here, but it fantastic to be back at such a big club.
"When a manager, especially one of Chris's stature wants to sign you so much, as a player it makes you feel really wanted.
"As soon as I heard of United's interest and having spoken to the manager I was eager to get the deal over the line."
And the Republic of Ireland international is looking to hit the ground running at S2.
He added: "I've two fantastic years at Brentford, I can't speak about them highly enough and we had a very good team there.
"But now I really want to kick on at Sheffield United. I love a team in red and white stripes and I just can't wait to get going again at Bramall Lane.
"I've been back with Gillingham and last season with Brentford, the place was rocking on the opening day of the season.
"The fans have always been unbelievable here and I can't wait to walk out as a Blade now."