Manchester United boss Sir Alex Ferguson said Carlos Tevez will make his debut for the club in Wednesday's league game at Portsmouth.
Tevez has praised United's "humble" players
The 23-year-old completed his move to United last Friday and is set to start the game as a result of the recent injury to fellow forward Wayne Rooney.
"Carlos will start on Wednesday against Portsmouth," said Ferguson.
"I would have preferred to wait for the Manchester City - that would have given him a few more days' training."
He added: " "But for the forthcoming few weeks, he will fill the position Wayne would have occupied."
At the official unveiling of the Argentina international, Ferguson said that the player's heroics for West Ham last season convinced him that the striker was worth bringing to Old Trafford.
Tevez helped the Hammers avoid relegation, including grabbing the winner at Old Trafford in the last game of the 2006-2007 campaign.
"He made a big contribution by saving them from the drop," added Ferguson.
"West Ham won something like seven out of nine games in the run-in, which was championship form, and most of those victories were down to Carlos."
The United manager said he would have sealed the Tevez deal earlier but was unable to because of "complicated" factors.
The Argentine joined the Old Trafford outfit after his agent Kia Joorabchian paid West Ham a £2m settlement.
The Tevez saga began in April when the Hammers were fined for breaching league rules over the signing of the striker and his Argentine team-mate Javier Mascherano, who has since joined Liverpool, in August 2006.
All great players need to play with each other - we are 50% similar
The Hammers' response was to tear up an agreement they had with Joorabchian - who claimed to own the striker's economic rights.
But when it emerged Tevez wanted to join United, the Hammers, backed by the Premier League, insisted they should receive the transfer fee, prompting Joorabchian to take legal action.
Joorabchian eventually agreed to pay West Ham £2m to release Tevez from his contract, allowing the Argentine to join United on a similar deal to the one that took Mascherano to Anfield in January.
"We had been watching him for a long time but we realised that the whole situation regarding ownership was complicated," conceded Ferguson. "But Mascherano going to Liverpool helped clarify a few things for us."
We are not looking at two years, we are looking at a long-term arrangement
Man Utd chief executive David Gill
United are reported to have paid Joorabchian £10m for what amounts to be a two-year loan term with the option to turn the transfer into a permanent deal at any stage before the contract expires.
United have first refusal on Tevez, who cannot leave for another club without the Red Devils first waiving their right to buy.
"Everything is in place for Carlos and Manchester United to agree a long-term deal and we are very comfortable with the arrangement," said Old Trafford chief executive Gill.
"We are looking at it very positively with a view that he will be the player he can be for Manchester United and that it will be an easy decision to exercise our option.
"That is our goal. We are not looking at two years, we are looking at a long-term arrangement."
Tevez said: "I am happy to be with a group of people who are not only football stars but humble as human beings.
When asked whether an eventual partnership with a fit Wayne Rooney would work because of their similar styles, he said: "All great players need to play with each other - we are 50% similar."