Carlos Tevez will be asked to fire up Manchester United's planned assault on the Premier League title - by immediately covering for the loss of Wayne Rooney.
The champions stalled on the grid yesterday by failing to beat Reading on home soil, an outcome accompanied by the awful news that Rooney had fractured his foot in an accidental collision with Michael Duberry.
Sir Alex Ferguson has confirmed Rooney will be out of action for two months, meaning he will miss eight Premier League games - including the September 22 showdown with Chelsea - United's opening two Champions League group fixtures, as well as England's crucial Euro 2008 qualifiers against Israel and Russia next month.
During a late evening phone call to England coach Steve McClaren, Ferguson did express confidence Rooney would be fit for the October double-header with Estonia and Russia.
In the meantime, McClaren needs to make alternative arrangements - probably in the form of Liverpool's Peter Crouch - while Ferguson, who is still without Louis Saha and Ole Gunnar Solskjaer, must plunge Tevez into action quicker than he had hoped.
'Carlos will start on Wednesday [away to Portsmouth],' revealed Ferguson.
'Ideally, I would have preferred to wait for the Manchester City game on Sunday - which would have given him a few more days' training.
'But for the forthcoming few weeks, he will fill the position Wayne would have occupied.'
Although Tevez was confirmed as a United player only on Friday, he has been training with the Red Devils for almost a fortnight.
Ferguson accepts the Argentina international may be slightly rusty, having not played a game since his country reached the final of Copa America four weeks ago.
However, the United boss has seen enough in training to feel Tevez can make a positive contribution at Fratton Park.
'There is no doubt in my mind Carlos was the major reason why West Ham stayed up last season,' said Ferguson.
'His performances in the Premier League last season is the foundation on which our opinion of him is based. But sometimes you get more of a feel from training, and he has been absolutely brilliant.
'I have been very impressed, not just by his aptitude for work but the receptive manner in which he has approached the sessions.'
Ferguson does expect Rooney to be training within the two-month timescale. Yet mindful the England forward was back in action six weeks after the last of his previous two broken metatarsals but miserably failed to do himself justice at the World Cup, the United boss will not be rushing him back.
Neither will he be charging into the transfer market again, after spending upwards of £50million strengthening his squad this summer.
The pressure is therefore on Tevez to hit the ground running. But the former Boca Juniors player - sent off in a friendly on his first appearance at Old Trafford in 2002 and a scorer on his second, netting the goal that kept West Ham up on the final day of last term - shows no sign of being overwhelmed by it.
'I have never felt pressure when I play football,' he said.
'Whenever I go on to the pitch I try to enjoy myself.'
Tevez acknowledges it has been 'impossible' to avoid the controversy surrounding his proposed move to United.
Yet it was only as the Copa America reached its conclusion that he began to get some idea what a fuss his long-time association with Kia Joorabchian was causing.
'I started to realise - because each game passed in the Copa America and still the matter was not resolved,' he recalled.
'But I never felt I would be forced out of the game.
'It hurt me to leave West Ham anyway, but the lure of Manchester United was just too much.'
Ironically, a move to United was recommended by a man now doing his best to leave - Tevez's international team-mate Gabriel Heinze.
Whether he is cleared to join Liverpool next week or not, Heinze would be regarded as a success story at Old Trafford - unlike compatriot Juan Sebastian Veron, or fellow South Americans Kleberson and Diego Forlan, who all failed to make much of an impression.
But having already adapted to life in England, Tevez should be a different case - and the player himself is eager to make his mark.
'It is a big blow to lose Wayne,' he said.
'He is a great player and he will be very difficult to replace.
'But at a big club like Manchester United you hope to have a number of players who can slot in.
'This is a massive step for me. Now I need to write my own piece of history at the club and do everything I can to help Manchester United be successful.'