The 19-year-old defender arrived at Bramall Lane on a season-long loan from Arsenal in the summer, but Blades manger Micky Adams has signed Neill Collins from Leeds on a permanent basis.
Adams said: "Under the circumstances, having brought in Neill Collins, who is also a centre-back but on a permanent deal, we felt that it was something we could do, especially as it frees up a loan.
"I would like to thank Arsenal and Kyle for their help over the last few months and wish him well as his career develops.
"It's importantwe start building continuity in the team, especially in defence, as soon as we can, and that must be based on having players here who belong to this club and have its interests at heart."
Source: PA
Source: PA