Former Chelsea forward Kalou will be out of contract at Hertha Berlin at the end of June and is in talks with the Rio de Janeiro giants.
However, they are hopeful of getting a move for another former Ivory Coast international over the line soon.
"He already has the pre-contract, but he asked for just one more detail in the contract that was sent to him," Botafogo official Carlos Augusto Montenegro told SporTV.
"I think it's okay. And if no presidential candidate for Vasco appears at his house, I think that maybe he will come."
Kalou, who is in a relationship with a Brazilian, was suspended by Hertha in May after being seen on camera flouting social distancing guidelines.
Botafogo have reportedly offered the 34-year-old an 18-month contract amid interest from European clubs.