The Blades announced they have paid Bournemouth a "substantial undisclosed fee" - reported to be in the region of £18.5million - to bring back Ramsdale. 

Having left Sheffield United in January 2017, the 22-year-old started 37 games for Bournemouth in the 2019-2020 season, though was unable to prevent the Cherries suffering relegation

Ramsdale has agreed to a four-year deal to seal his return, while Henderson is rumoured to be on the verge of signing a new contract at Manchester United. 

"The goalkeeping situation is something we have to make sure we get right," Sheffield United boss Chris Wilder told the club's website. 

"This is not about Dean, it's about bringing Aaron in, but Dean was outstanding for us for two years. We know a lot about Aaron, we've watched him develop on loan at Chesterfield and then AFC Wimbledon and obviously we've watched him this season too. 

"I'd like to thank the board for their backing given the situation. Aaron is certainly amongst the best young goalkeepers in this country and we are delighted to have him."

Henderson enhanced his reputation during his time with the Blades, helping them secure a ninth-place finish in the Premier League following their promotion from the Championship. 

It is unclear if the keeper will go out on loan again or remain at Old Trafford to provide competition for David de Gea, but the Red Devils are reportedly close to agreeing terms on a long-term deal for the England Under-21 international. 

In a statement posted on Twitter, Henderson thanked all those at Sheffield United, including the fans, following his successful spell there.

"I will look back at the last two years as an important chapter in my career and more than anything, I'm grateful to have had the opportunity to learn and develop with such a class group of lads," he wrote.

The 23-year-old signed off the post by expressing his excitement at the next chapter of his career, followed by: "Once a Blade, always a Blade!".