South Africa wicketkeeper Quinton de Kock has been taken for a scan on his right index finger, which he hurt during the Wellington Test.
De Kock injured himself in the field and South Africa will wait for results of the scan before making any calls on his availability for the Hamilton Test. De Kock was not present at the start of Wednesday's training session but was set to join the squad later.
South Africa have a reserve gloveman in their squad, the Titans wickektkeeper Heinrich Klaasen, who is yet to make his international debut.
New Zealand also have an injury concern ahead of the third Test, with fast bowler Trent Boult recovering from an upper leg injury. Boult has bowled lightly for the last two days but New Zealand wicketkeeper BJ Watlingt said Boult was not yet 100% fit and a call on his availability would be taken later in the week.
The third Test begins at Seddon Park on Saturday.