Isaacs started his professional career with the People’s Team in 2003, going on to score 51 goals in 158 appearances for the 2001/2002 PSL champions.
Santos manager Boebie Solomons confirmed 'Appels' is back with the Cape-based club.
“Yes, Appels is training with the club,” Solomons told KickOff.com.
“He has a very good soccer brain but he is not up to scratch though and needs to get his fitness back. But that’s understandable as he did not play for months.
“I was also the one who promoted him from the youth ranks and made him a professional player, hence he has big respect for me. But we’ll see how he adjusts going forward.”
The 31-year-old has been out of football since February after Ajax released him for allegedly stealing soccer boots.