Manchester United are being held back by inconsistent performances from their top players, former defender Rio Ferdinand said after their shock 2-1 defeat by bottom side Sheffield United in the Premier League on Wednesday.

United, who would have replaced Manchester City at the top of the table with a win, have been on a good run in recent weeks and delivered an inspired performance to knock bitter rivals Liverpool out of the FA Cup on Sunday.

"Last week (against) Liverpool, tremendous performance," Ferdinand told BT Sport. "(Against) Bottom of the league Sheffield United dour, lifeless at times. The inconsistencies don't win you the league.

"It's what we said about Manchester United for many, many months that the inconsistencies of individuals on this team is what's holding them back."

United's big-name players were anonymous against Chris Wilder's side, who had won only one league game all season coming into the match.

"Bruno Fernandes, who they've relied on so heavily in recent weeks, months, didn't get it going today. Paul Pogba the same," Ferdinand added.

Manchester United face a trip to Arsenal in the league on Saturday.