Blades boss Chris Wilder is delighted the Blades fought off competition from a Championship rival, before handing goalkeeper Simon Moore a new three-year deal.
The 28-year-old was subject to interest from recently relegated West Bromwich Albion, but after United repelled their advances, Moore put pen-to-paper on improved terms, making him contracted at the Lane until the summer 2021.
The manager explained: "We've never wanted to lose Simon and we didn't want to be in this position because it can be unsettling when there is interest in a player you don't want to sell.
"It's good for us as a club that we've managed to keep the continuity of the goalkeeping department intact and for Simon he's extended his stay and improved his contract.
"It's been our intention to speak to those in their final year once the window shut, it's been speeded up with Simon, but we'll continue to monitor and assess situations with the likes of Billy, Basham and Couttsy."
Wilder added: "We've planned since day one and we don't want to come to a situation, unless it's our choice, that we're running contracts down and we certainly not in those position with those mentioned.
"West Brom are a huge club in the division have come down from the Premier League and we've spoken before about parachute payments, so financially he probably would have got a better deal there.
"So we had a decision to make and we've made what we believe is the right one, he is a great lad, a fantastic character and most importantly and excellent goalkeeper."