Horn, a 28-year-old from Queensland in Australia, has already been touted as the next opponent for current WBO champion Manny "Pacman" Pacquiao.
Pacquiao's American promoter Bob Arum is understood not to be interested in matching his charge against No 3 contender Timothy Bradley.
That is because the two fighters fought each other for the third time in April. Arum and Pacquiao's fans want fresh blood and see Horn as just the right opponent.
Victory for Horn against Funeka will make him the mandatory challenger for the vastly experienced Filipino legend, Pacquiao, who has 38 knockouts from 59 wins in 67 bouts.
That is because Horn is rated No 2. Funeka occupies the No 8 spot.
But defeat will see Horn's aspiration of fighting Pacquiao go up in smoke. He will also forfeit his top spot.
It is unclear though if Funeka will take over that position if he wins.
Funeka, 38, still remains a dangerous boxer despite his age.
The hard-hitting former SA junior lightweight and junior welterweight, WBF junior welterweight and IBO welterweight holder from Mdantsane boasts 31 knockouts from 39 wins against five losses and three draws.
Horn has 10 knockouts from 15 wins and a draw. Horn last boxed on October 21 when he stopped Rico Mueller within the distance to retain his IBF Inter Continental belt in Australia. Horn has boxed 88 rounds.
The fight between Horn and Funeka will feature in the same bill where Joseph Parker and Andy Ruiz Junior will fight for the vacant WBO heavyweight belt.
Parker, a New Zealander based in in the US, is a 2010 Olympics silver medallist and a Commonwealth champion. He is undefeated in 21 bouts, while Mexican Ruiz Junior also boasts a clean slate of 29 bouts.