Manchester United defender Nemanja Vidic believes that teammate Rio Ferdinand still has enough "quality and ability" to compete at the highest level in football.

The 32-year-old has come under criticism after Sir Alex Ferguson admitted that the England international was no longer his first-choice defender in the Red Devils' starting XI.

"When you look at what is happening to Rio over the last few weeks, this is a player who played in most of the big games last season, helped us win the Premier League title and reach the Champions League final and yet, after one game, people are saying he is not good enough anymore," said Vidic.

"I think this is wrong and Rio showed that [against Sunderland]. He showed class, he showed determination, as well as his ability to help the players around him.

"Sometimes, when you have been at the top a long time like Rio has, people judge you on your age. They are waiting for one bad game to say he is finished."

The 30-year-old believes that Ferdinand proved his value during United's 1-0 win over Sunderland in the Premier League at the weekend.

"What he did [on Saturday] is the perfect way to show he is not finished," he added. "He showed strength of character. He showed everyone that he still has the quality and ability to play at the top level."

Reports have claimed that Ferdinand could be forced to exit Old Trafford in the near future.