South Africa named two uncapped fast bowlers in a 16-man squad for a two-match Test series against Pakistan starting in Centurion on December 26.
With an entire battery of fast bowlers unavailable, left-armer Kwena Maphaka and Corbin Bosch were added to the team that beat Sri Lanka in Gqeberha this month.
Maphaka is an 18-year-old prodigy who has already been capped at the Twenty20 international level while Bosch, the 30-year-old son of former Test fast bowler Tertius, has yet to play for the senior national team.
South Africa included all-rounder Wiaan Mulder and left-arm spin bowler Keshav Maharaj in the squad, but both selections are subject to fitness.
Mulder suffered a broken right middle finger in the first Test against Sri Lanka while Maharaj suffered what Cricket South Africa described as "an acute groin strain" while warming up for the first one-day international against Pakistan in Paarl on Tuesday.
Maharaj was due to have a scan on Wednesday to assess the severity of the injury.
Bosch, who has a first-class batting average above 40, could come into contention if Muller is unfit, while Senuran Muthusamy, also a left-arm, is the only other spin bowler in the squad if Maharaj is ruled out.
South Africa will be assured of a place in next year's World Test Championship final if they win at least one Test against Pakistan – but their bowling resources have been seriously depleted.
Fast bowlers Anrich Nortje, Nandre Burger, Gerald Coetzee, and Lizaad Williams have all been sidelined. It will be a blow if Maharaj, South Africa's premier spin bowler, cannot play.
"We head into this series with a clear focus, with a spot in the World Test Championship final being the pot of gold at the end of the rainbow," South African coach Shukri Conrad said in a CSA statement.
Squad: Temba Bavuma (capt), David Bedingham, Corbin Bosch, Matthew Breetzke, Tony de Zorzi, Marco Jansen, Keshav Maharaj, Kwena Maphaka, Aiden Markram, Wiaan Mulder, Senuran Muthusamy, Dane Paterson, Kagiso Rabada, Ryan Rickelton, Tristan Stubbs and Kyle Verreynne (wkt).