Wayne Rooney insists Manchester United can snatch the Premier League title back from Chelsea.
United have now gone three seasons without the championship and are long odds against to end the mini-drought this season.
While Chelsea have been spending big to capture Michael Ballack and Andriy Shevchenko, the Red Devils only close-season buys to date are Michael Carrick, who will miss the start of the campaign with ankle ligament damage, and goalkeeping understudy Tomasz Kuszczak.
In addition, Ruud van Nistelrooy has left Old Trafford so it could be argued the Red Devils are actually weaker than they were 12 months ago.
However, while he acknowledges the loss of Van Nistelrooy is 'a blow', Rooney is adamant United retain enough quality to give Chelsea a far sterner test than they have experienced for the past three seasons.
'We are credible challengers,' said Rooney.
'This is a big season for us. We have said it before but we have to win it this year.
'Manchester United are one of the biggest clubs in the world and to go three or four seasons without winning the league is not good enough.
'We have the talent and quality to win the title but we have to work harder as a team and sign the players that can win us the league.'
Rooney insists he is not concerned about the reputations of Ballack and Shevchenko, believing United would be better served by concentrating on their own performances.
To that end, patching up relations with Cristiano Ronaldo should have helped.
Rooney remains disappointed at Ronaldo's involvement in his dismissal during England's World Cup quarter-final defeat to Portugal in Gelsenkirchen.
But the former Everton star is happy to confirm the pair have now moved on and has called for the boo-boys who were out in force at Oxford on Tuesday night to lay off his young team-mate.
'I would rather he didn't get any stick,' said Rooney.
'You do not want to see any player get booed.
'Unfortunately, whenever England do not do well in a World Cup or a major tournament, people look for a scapegoat. This year, people turned on Cristiano and tried to make him that.
'I am not going to lie, I was disappointed with his involvement in the sending-off. But that is in the past now. He was playing for his country, I was playing for mine.
'But I think he is big enough to deal with anything that come his way. You saw that the other night. Cristiano got booed but he still scored two fantastic goals.'
Rooney was speaking at the launch of his recently-released autobiography 'Wayne Rooney: My Story So Far'.
Offering forthright observations across a wide range of topics, the England striker admitted he was not happy at being told to play as a lone front-man by Sven-Goran Eriksson during the World Cup and expressed the hope new coach Steve McClaren will not force him to do it again during the Euro 2008 qualifying campaign.
Rooney also endorsed the fears of manager Sir Alex Ferguson that he is now a target for referees seeking a trophy dismissal.
The 20-year-old has been sent off three times in the last year, culminating in last Friday's early departure against FC Porto in Amsterdam which could yet earn him a three-match Premiership ban.
'Possibly, I am getting picked on,' he said.
'Referees get a lot of headlines with some of the decisions they make.
'I am not having a go at the referee but it is just the way the game has gone and sometimes, players have to take the consequences of that.
'In the Premier League the referees let it go a bit but the foreign refs slow it down and are quick with the cards.'
Rooney will get to meet Kuszczak for the first time tomorrow after the Polish keeper completed his protracted move from West Brom.
The 24-year-old has signed a season-long loan deal, which will turn into a permanent transfer in 12 months' time, ending a long-running saga which has lasted most of the summer.
Youngsters Luke Steele and Paul McShane have joined the Baggies as part of the deal, which will also see Ben Foster return to Watford for a second year as Ferguson looks to generate some competition for the point where Edwin van der Sar retires, probably after Euro 2008.
'Tomasz will add good quality to the squad,' said Ferguson.
'He has plenty of ability and knows what challenges the Premiership presents.
'I am sure he will benefit from working alongside a great keeper like Edwin van der Sar.
'Also, I am pleased that Ben Foster will be able to play regular first team football at Watford and I am sure he will continue to develop as a top flight goalkeeper.
'We are building great strength in depth in that position at United.'