With goals proving hard to come by last season, Siwelele have turned to Mabena - snapping up the free agent after he failed to agree on a renewal with Platinum Stars.
As reported by KickOff.com yesterday, the 30-year-old hitman links up with Celtic on a two-year-deal.
Lucky Baloyi joins the Free State-based club after being offloaded by Kaizer Chiefs following a season in which he made only seven appearances for the Glamour Boys.
The duo join alongside Given Mashinkinya, who arrived at the club yesterday from Cape Town City as part of a swap deal with the departing Lyle Lakay.
Celtic CEO Khumbulani Konco confirmed the capture of Mabena and Baloyi, clarifying the lengths of their respective contracts.
"Yes, both players have signed two-year contracts plus an option," Konco tells KickOff.com.