New Sunderland head coach Dick Advocaat warned Friday that he will need to bring in sweeping changes if the club are to avoid relegation.

The 67-year-old was unveiled at a press conference at the club's Academy of Light training headquarters ahead of his first Premier League game in charge at West Ham on Saturday.

Advocaat's team are sitting just one point clear of the drop zone.

And the Dutch coach said: "In principal, every thing you do in football is a challenge and you want to do as well as possible.

"But we are now in a situation where we are playing more or less at the bottom of the league, so something has to change."

Advocaat who arrives after a spell as manager of the Serbia national team, admitted he is relishing the challenge of guiding a squad which faltered alarmingly during the latter weeks of predecessor Gus Poyet's reign away from trouble.

He took up the reins on Tuesday and has had three days to work with his players, although he revealed few of them were strangers to him.

Advocaat said: "In Holland, we can see all the games in England - everything is on television, so I knew the squad, I knew the players, plus the fact that we have a great stadium and great fans.

"With the support of them, we must do it. I have a good feeling about the squad after the last three days, so why not?"

The Black Cats are without a win in six league games and seven in all competitions, a run which has plunged them into a second successive survival fight.

Advocaat needs all the players he can get his hands on if he is to engineer an escape, and he could have at least one more to call upon this weekend after the club lifted its suspension of winger Adam Johnson as a police investigation into an allegation of sexual activity with a girl under 16 continues.

However, Advocaat declined to reveal whether or not the 27-year-old, who had been training by himself after the ban was imposed, would be included in the travelling party.

He said: "What I always do, I pick the squad after the final session. We still have some injuries, we don't know exactly who will join us.

"Always after the last training, I will pick the squad so it's the same for everybody."

Meanwhile Poyet spoke Friday of his pride in taking the Black Cats to Wembley for a League Cup final, of winning three derbies with Newcastle, but above all of 'a miracle unbeaten run' that kept them up in 2014.

"When I arrived in October 2013, Sunderland had played seven matches and lost six, gaining only one point, and they were bottom of the Barclays Premier League.

"Thirty-one matches later at the end of the season, we had won 10 and drawn eight, taking us to the complete safety of 14th position.

"I will always remember fondly that miracle unbeaten run, a vein of form for which I was honoured to be short-listed for the Barclays Premier League Manager of the Year Award.

The 47-year-old Uruguayan was sacked on Monday after a 4-0 defeat to fellow strugglers Aston Villa.