De Jager suffered a bruised knee in the Springboks' 23-17 loss to Australia in Brisbane and has been ruled out for two weeks, the South African Rugby Union confirmed on Sunday.
The 32-year-old Alberts, who has not featured for the Boks since the World Cup last year, can play in the second row, as well as cover the flank and number eight positions.
The Stade Francais forward will join the team in Christchurch on Monday, hoping to add to his 38 caps.
Scrumhalf Faf de Klerk (chest) and fullback Johan Goosen (ankle) both underwent scans after the loss to Australia but will remain with the squad.
South Africa have a single win from their three matches in the Rugby Championship this year after back-to-back losses to Argentina and Australia.
(Reporting by Nick Said; editing by Sudipto Ganguly; nick.said@thomsonreuters.com; +27832722948; Reuters Messaging: Reuters Messaging: nick.said.thomsonreuters.com@reuters.net)
