Brits, who was in South Africa on holiday and was at the first Test as a fan, retired after Saracens' Premiership final victory over Exeter but has unexpectedly been called up by Springboks boss Rassie Erasmus.
"Last week wasn't the start we wanted and this wasn't the home start we wanted".
Eddie Jones' side looked good for the first 20 minutes and the last 10, but lost its way badly in the middle.
The Springbok team to face England in the second Test in Bloemfontein's Toyota Stadium will be named on Thursday.
"Owen Farrell has settled in well to his new role, with the senior players supporting him, and there is a good feeling within the camp".
By the break, the Boks were ahead by 29-27 after a brace of tries by Sbu Nkosi, who was on debut for South Africa, as well as Willie le Roux and Faf de Klerk, both of whom were back in green and gold for the first time since 2016.
"We knew that wasn't what we worked on during the week. I'm proud of the guys - they showed character and it's something we can take forward". "I was worried‚" said Erasmus. It could have gone bad really for us. "We only scraped through‚" said Erasmus.
The Sunday social was pre-planned by the players as they hosted a barbeque in the hotel grounds as a means of bonding and shaking off the miseries from the stunning 42-39 reversal at Ellis Park.
"There were some great individual performances, but we still made too many unnecessary errors and we have a lot to work on. It is going to be a massive one in Bloemfontein".