They have turned their season around after a remarkable run of form under new boss Paul Heckingbottom. Unbeaten since October at Bramall Lane, they moved back into the top six at the weekend with a 2-0 victory over neighbours Barnsley.
The biggest threat to their promotion ambitions this season is surely their mounting injury list, which has seen the entire right side of their defence decimated and a number of strikers ruled out for varying lengths of time.
United looked at free agent Andre Wisdom but decided against signing him, although Heckingbottom admits United are “serious” about bringing a free agent in.
So we scoured the free agent market to pick out 12 players who could possibly do a job for United – click through our photo gallery to have a look ...
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1. Winston Reid
Formerly of West Ham, the New Zealand international was most recently on loan at Brentford, playing in last season’s play-off final to help the Bees into the Premier League. Getting on at 33 but could be good cover for John Egan and help Kacper Lopata and Co. develop Photo: Catherine Ivill
2. Hal Robson-Kanu
Another potential option in attack, Robson-Kanu would offer a physical presence for the run-in after leaving West Brom recently. Can also play wide Photo: Pool
3. Marc Navarro
A player with experience, albeit briefly, of playing in England from a spell at Watford which came to an end last summer. Mainly a right-back, he can also play in the centre – which could be ideal considering United’s troubles in that area Photo: Richard Heathcote
4. Jerome Sinclair
Out of contract after leaving Watford at the end of last season, Sinclair has hardly set the world alight since leaving Liverpool as a youngster but clearly has some ability to have played for the Reds and England’s youth teams. If Billy Sharp is out for any time, he may provide something different Photo: Dan Istitene