* Hulkenberg returns as Perez's stand-in
* German raced for Renault last season
* Mexican Perez tested positive for COVID-19 (Adds details)
By Alan Baldwin
SILVERSTONE, England, July 31 (Reuters) - Nico Hulkenberg declared himself up for the challenge after returning to Formula One, in borrowed overalls and a buttock-numbing seat, at the British Grand Prix on Friday as a replacement for quarantined Mexican Sergio Perez.
The German, a veteran of 177 grands prix, raced with the Racing Point team when they were known as Force India and competed for Renault last season before losing his seat and turning his hand to TV punditry.
Perez is in self-isolation after becoming the first F1 driver to contract the COVID-19 virus.
"Having to find a replacement for Sergio at short notice is no easy task, but in Nico we've got a fantastic supersub who the team knows very well," said team boss Otmar Szafnauer in a statement.
"He's certainly being thrown in at the deep end, but he's a fast learner and I'm sure he will get up to speed quickly."
Hulkenberg, a Le Mans 24 Hours winner who is famous in Formula One for never having reached the podium in a career that started at Williams in 2010, said he had been on his way to the Nuerburgring when he got the call.
"That was less than 24 hours ago, so it feels a bit surreal for me right now, but I like a good challenge and this is certainly one," said the 32-year-old.
Szafnauer said Hulkenberg flew from Cologne to Birmingham on Thursday evening with boots and helmet, underwent COVID testing, took in 45 minutes on the simulator and walked into the paddock 10 minutes before practice started.
"We got the go from Eurofins (the testers) I think at a quarter to 11 saying his test came back negative so then we had to quickly get him in the car," said the boss.
Hulkenberg, wearing a spare pair of team mate Lance Stroll's overalls, was ninth fastest in the opening session. At one point he reported over the radio that "my right ass-cheek is getting quite numb."
He could remain in the car for the 70th Anniversary Grand Prix at Silverstone, the weekend after the British Grand Prix.
Perez tested on Wednesday, when a seven day quarantine requirement was in place for positive cases but Britain changed that period to 10 days on Thursday.
"If it's certain he is out for two (races), then Nico will drive in both," said Szafnauer. "But there is a bit of uncertainty and we're still not sure if it's seven or 10 days." (Reporting by Alan Baldwin, editing by John Stonestreet and Christian Radnedge)