At half-time, the Sky Sports pundits pulled no punches.
“That could have been career-ending,” former England midfielder Jamie Redknapp said. “He has cost his team. I feel so sorry for Chris Wilder. Scandalous tackle.”
Luton captain Tom Lockyer said: “If that was my team, I would be raging.”
However, Cheltenham Town centre-back Curtis Davies, 38, said: “Back in the day that was seen as a bit of a freebie. You can get the ball but also take the man.”
Sheffield United started the match bottom of the table, seven points adrift of Luton, who occupied 17th spot, the final position outside the relegation zone.