The former England international, who cost a club record £4m from Everton last summer, has still to recover from summer surgery.

Beattie's absence will open the door for Darius Henderson to make his Blades debut in tomorrow's televised opening game of the season at Birmingham City.

Doncaster-born Henderson arrived in a £2m move from Watford this summer and is likely to partner Billy Sharp in attack.

"It's disappointing not to have James available but he is only three to four weeks away which is good news," said manager Kevin Blackwell. "His absence gives other lads an opportunity to stake a claim and I wouldn't want to be one of the 11 that loses their shirt right now because it could be a long time before they get it back again."

Beattie was the Blades's leading marksman with 22 goals last season and his performances attracted attention from Premier League clubs including Sunderland, Middlesbrough, and Aston Villa. However, despite a summer of speculation, the Blades received no official bids.

Over the next three weeks, the Blades have four league games against Birmingham, QPR, Blackpool, and Cardiff City as well as a Carling Cup tie against Port Vale. Beattie is likely to return to action after the international break on September 13 when the Blades visit Derby County.

The Blades will also be without wingers Keith Gillespie and David Carney for tomorrow's opener.

Gillespie is ruled out for a month with a sprained ankle and Carney is away on Olympic duty with Australia.

Blackwell, meanwhile, admits that he is finally enjoying management again after enduring difficult times at his previous two clubs, Leeds United and Luton Town.

The Blades so nearly qualified for last season's play-offs after Blackwell's arrival sparked a run of eight wins from the final 11 games.

His impact led to a permanent deal being offered in the summer and the Blades start the season among the favourites for gaining promotion to the Premier League.

"It would be nice to think my luck has finally changed," he smiled.

"When I arrived someone gave me a Blades shirt with the word 'Bankrupt' on the back. Hopefully that won't happen at Sheffield United because, if it did, I don't think I would ever get a job in football again!

"This is a great job, I can concentrate on football," he added. "I don't have to deal with selling my best players, coming to work and not knowing if I have got a club, or lending money to players because they have not got their wages!"

Sounding a note of caution, Blackwell added: "I think this club can go wherever it wants to go. Our finish last season showed we have the quality. Our aim is the Premier League and the chairman wants us to be a top 10 club in the next five or six years.

"Expectations rise and when they are not quite met, there is normally one fall guy – but I have got to accept that and deal with that. I just hope people realise that success is not always instantaneous."