United Women have completed the signings of two experienced FA Women's Super League players.
Sam Tierney and Beth Merrick bolster Carla Ward's side as the Blades continue to prepare for an inaugural season in the FA Women's Championship.
Sheffielder Sam, an England youth international, spent eight years with United's Regional Talent Club before switching to Doncaster Belles, where she won the WSL2 title last season.
Blades chief Ward commented: "We are absolutely delighted to get Sam back to United, she was a top target of ours from the word go, she can operate anywhere in the back four or also in midfield. Last season was probably her best and to beat off competition from two WSL1 sides is pleasing and shows what we are trying to build here."
Tierney added: "The biggest thing that attracted me back to the club is the ambition of both the club and all the staff, it's exciting to be a part of something new and in an environment that is pushing to progress and challenge from the start. It's a club that has been a huge part of my youth development and one I hope will be able to develop me more as a player this season."
The capture of Merrick from Aston Villa is also a coup.
Also an England youth international, winger Merrick spent 11 years at Villa and broke into their first team at the age of 16.
She said: "When I came to meet members of the club it just felt right and I was very exciting straight away. The coaching staff and the plans the club have for the squad are amazing. The history of the city is huge too and something most football fans are well aware of."
Boss Ward added: "Again, I'm delighted with this capture. Beth is an exciting young talent that brings a lot of quality to this squad, she's been in only a matter of days and already has shown what an excellent addition she will be."