Abendanon has already joined up with the squad ahead of the second Test against the Springboks on Saturday in Johannesburg, where he attended the weekend wedding of Bath team-mate Pieter Dixon.
The 25-year-old Abendanon was born in Johannesburg and made his Test debut in nearby Pretoria against the Springboks in 2007. He earned his second and last Test cap against France at Twickenham later that year.
Harlequins star Brown will return home for an operation on his thumb.
England’s backline will have to be further shuffled for the second Test after Brad Barritt, another South African-born player, underwent a minor operation at the weekend for a lacerated eyeball.
“Barritt won’t figure in this week’s games, but will join us in Johannesburg later this week,” England media manager Dave Barton told Reuters on Monday.
The 25-year-old Barritt has remained in Durban, where he was resident when he began his professional career with the Natal Sharks, because he is not yet able to fly.
Abendanon took a full part in training on Monday and will come into contention for selection for the team to play the Southern Barbarians in Kimberley on Wednesday. That team will be announced later on Monday.
South Africa staged a second-half rally to beat England 22-17 in the first Test in Durban last weekend, with tries scored by flyhalf Morne Steyn and centre and new captain Jean de Villiers, although the tourists were outdone up front by the Springbok pack.