Carlos Queiroz, Manchester United’s assistant manager, has raised doubts about his future as he considers whether to pursue a new challenge at the end of the season. Queiroz, 53, is highly regarded within Old Trafford, where he is considered by some to be the most obvious candidate to succeed Sir Alex Ferguson as manager when the Scot finally retires, but, having entered the final six months of his contract, the Mozambican-born coach is unsure where his future lies.

“In June my contract finishes and it will have been three years for me [since returning to United after an unhappy spell as coach of Real Madrid],” Queiroz told O Jogo, the Portuguese newspaper. “Whether I stay or not depends on the decision of Alex and the club’s new owners. Also I may decide to leave the club for other projects. I wait to accept a big project. Initially I left Portugal for six months and now it has been 11 years. I have still not received a spectacular project for me to reject the option [of returning to Portugal].”

Queiroz has been considered for various jobs in recent months, including the vacancy at Benfica last summer and the position as coach of the United States national team, but he is known to be excited by the prospect of replacing Ferguson when the 65-year-old retires.

Although vilified by some supporters early last season, when he was blamed for the team’s conservative tactics and for the fallout that led to Roy Keane’s acrimonious departure, Queiroz is held in particularly high regard by David Gill, the chief executive, and has been cited by Ferguson for his influence in the team’s resurgence this term.

United seem certain to offer Queiroz a new contract and to give him vague assurances, as they did on his return from Madrid in 2004, that he will be well-placed to succeed Ferguson when the time comes. However, with the manager claiming last week that he intends to stay on for at least another two years, his much-travelled assistant appears to be getting itchy feet, as he did before leaving for Real in June 2003 after a successful first season in Manchester.

Despite the minor setback of Monday’s 2-2 draw away to Newcastle United, Ferguson remains bullish about his team’s prospects of winning their first Barclays Premiership title since 2003, particularly with Henrik Larsson officially joining the club yesterday. Larsson, the former Celtic and Barcelona forward, has arrived on a ten-week loan from Helsingborgs and, although the 35-year-old’s stay at Old Trafford is due to be fleeting, he has already been pencilled in to make his debut in Sunday’s FA Cup third-round tie at home to Aston Villa, with Ole Gunnar Solskjaer also expected to figure. “I didn’t take Ole to Newcastle because he has played two games in four days and I thought he would be better resting ready for Sunday’s match,” Ferguson said. “He will play along with Larsson.”

Ferguson’s statement implies that Wayne Rooney may be rested on Sunday, having required treatment on a knee injury during Monday’s game, but, with Louis Saha ruled out with a groin problem, the manager’s plans for the FA Cup tie are unclear. Saha, who underwent a scan yesterday, is hopeful that he will be fit in time for the Premiership match away to Arsenal on January 20.

David Jones, the United midfield player, 22, will complete his £1 million transfer to Derby County this week, having impressed since joining the Midlands club on loan in November.