Barnsley are considering legal action against Sheffield United after the FA said yesterday that it is unable to take any further action against Chris Morgan over the challenge that left Iain Hume with a fractured skull.

Morgan captained the United team that lost 3-1 at home to Wolverhampton Wanderers last night as the Coca-Cola Championship leaders moved 12 points clear of third-placed Reading.

Hume, meanwhile, was released from Tameside General Hospital, near Manchester, after being readmitted on Monday with an infection. As he returned home, Barnsley said they were “extremely disappointed and concerned” that the governing body was closing the book on the incident in the match at Oakwell on November 8.

The United defender was cautioned for the challenge that left Hume’s relatives fearing for his life. The FA claims that because Andy D’Urso, the referee, saw the incident and made his judgment, it cannot take retrospective action. However, there is a precedent, when Ben Thatcher, then of Manchester City, was only booked for elbowing Pedro Mendes, who was playing for Portsmouth, in August 2006. After that incident, the FA suspended Thatcher for eight matches in addition to a six-match ban from his club.

“The decision by the FA to disconnect a violent act from its consequences runs contrary to the principles of civil and criminal law,” Barnsley said in a statement. “The FA’s failure to act has let Iain Hume down badly and the only option now is for recourse outside of the normal football processes.”

It is thought that the Barnsley board will reconvene with its legal advisers today, but that any action would initially be against United, as Morgan’s employers. “Iain wants to be left out of this to concentrate on recuperation,” Michael Walsh, Hume’s agent, said.

Kevin Blackwell, the United manager, sent Sam Ellis, his assistant, to the post-match press conference at Bramall Lane last night. “It’s not a relief because we never expected,” Ellis said. “We’re very sorry Iain Hume’s back in hospital; we don’t like the suffering the kid’s had. But as far as we’re concerned, it’s over and done with.”

Asked whether the controversy had affected Morgan, Ellis said: “I don’t think so. He’s not playing like it.”

Earlier, an FA spokesman said: “The FA has had to consider the challenge itself and not the outcome of it. The FA has been given express direction from Fifa that we cannot upgrade yellow cards to red. On this basis, we can only bring additional charges in the most exceptional cases and only if it can be proved beyond doubt that the actions of a player were a deliberate attempt to injure an opponent.”

United came under pressure last night as Wolves, despite having to substitute three players by the start of the second half, had too much class for Blackwell’s play-off contenders. Chris Iwelumo scored twice, taking his tally to 15 goals for the season, and Sylvan Ebanks-Blake claimed his eleventh before Matthew Spring’s consolation.

“We knew it would be a tough game and it was,” Mick McCarthy, the Wolves manager, said. “We’ve got one with concussion, one with a gash in his shin and another with a broken nose.”