Perez remains asymptomatic despite his positive test, and has explained his decision to travel to Mexico on a private plane following the last race in Hungary, which was within the FIA's code of conduct.
Perez said: "I'm extremely sad, definitely one of the saddest days in my career".
"A great effort by the team, I want to thank the night-shift guys who did an awesome job to fit me in the vehicle quite comfortably, and the FIA for turning it around so fast on the super-licence".
"I'm extremely sad, it's definitely one of the saddest [moments] of my career, the preparation we put in to this weekend to be 100 per cent ready for it, I knew I had a great vehicle, the team had done a fantastic job".
"I'm really sad this happened but it shows how vulnerable we all are to this virus", Perez said. Then I came back to Europe, same way, with all the protocols in place.
He added: "I want to thank my fellow drivers for all the support they have given me, my team, the authorities, the fans, certainly tough moments for me but I'm sure I'll come back stronger from this".
The German left Formula 1 at the end of previous year having been replaced by Esteban Ocon at Renault for 2020, but of course previously spent five seasons at the team then known as Force India, initially as reserve driver before racing for them in 2012 and between 2014-2016.
As per the agreement between Mercedes and Racing Point, the reserve drivers of Mercedes- Stoffle Vandoore and Esteban Gutierrez are also listed as Racing Point's reserve drivers.
Sergio Perez's Racing Point boss believes Formula One drivers could now be forced to stay in their bubbles for the rest of the season.
Racing Point team principal Otmar Szafnauer said: "In Nico we've got a fantastic super-sub who the team knows very well".
"I think there I got to grip pretty quickly with things". He has now been retested by the FIA and Formula 1, and that result came back positive.
"The last 24 hours have been a bit special, insane and wild", Hulkenberg acknowledged.
"It's obviously a hard situation for Racing Point and Checo. He's a buddy of mine, an old team-mate and I wish him a speedy recovery".
Hulkenberg is expected to continue for the team as long as Perez is out, but they were not able to confirm that on Friday.