LONDON (Reuters) - McLaren have recognised that they do not know just how good Mexican signing Sergio Perez really is.
The 22-year-old Formula One driver has failed to score a point in the four races since he was announced in September as successor to departing 2008 champion Lewis Hamilton, who will be racing for Mercedes next season.
Before the announcement, Perez had chalked up three podium finishes with Sauber.
"I think he's got a lot of talent but if I'm honest, I don't know," McLaren team principal Martin Whitmarsh told reporters when asked about his new signing's potential at the weekend's Abu Dhabi Grand Prix.
"We wouldn't have signed him unless we thought that he could go to another level, but we don't know," added the Briton.
Perez, whose Japanese team mate Kamui Kobayashi has scored 23 points in his last four races, is the same age as Hamilton was when he joined McLaren in 2007 for what was to turn out to be a sensational debut season.
The Mexican has been at Sauber for two years and was seen initially as a 'pay driver', someone who owes his seat as much to the financial backing he brings as his talent.
That notion changed this season, with Perez earning considerable praise for the way in which he has managed the tyres and fought for podium placings.
However, moving to McLaren, the second most successful team in Formula One by race wins and one whose drivers are expected to be fighting for the title, brings far more pressure than racing for mid-table Sauber.
Perez's team mate will be Britain's Jenson Button, the 2009 world champion who has won two races this season and become an integral part of a team that some had seen as built around Hamilton.
"There's been examples of drivers who have got a lot of talent and they can live with that pressure and deliver and others that can't," said Whitmarsh of the challenge ahead.
"I think it would be foolish of me to sit here and say, taking a very young driver, there's not an element of risk in it. But we wouldn't have done it unless we felt there was a possibility. Time will tell."
When McLaren signed Perez, Whitmarsh told reporters that he expected the former Ferrari academy driver to be competing to win in next year's Australian season-opener.
"We undoubtedly believe we can develop him into a world champion in fairly short order," he added of a youngster he aimed to 'sculpt'.
Ferrari president Luca di Montezemolo had said, when Perez was being mooted as a possible replacement for Brazilian Felipe Massa at the Italian team next year, that he did not consider the Mexican ready yet.
Perez, 15th in Abu Dhabi after collecting a stop/go penalty for causing a collision that brought out the safety car for the second time in the race, dismissed suggestions at the weekend that his form had suffered because of the McLaren contract.
"It's just a coincidence," he said. "I am fully focused...it's normal that people start to make up stories that I'm not doing very well because of the McLaren deal or whatever but it's not true."