England's Jonny Bairstow "could be one of the greats", according to former South Africa wicketkeeper Mark Boucher.
Boucher, who played 147 Tests and holds the record for most dismissals by a wicketkeeper with 555, revealed Bairstow has approached him for advice.
The 26-year-old is playing his 24th Test, but has made several errors behind the stumps in Centurion.
Boucher said: "It shows a good character who understands he is still learning, which is a fantastic trait."
But he has been criticised over his glovework since displacing Jos Buttler as keeper in the third Test against Pakistan in November.
In this game at Centurion, he has spurned chances to dismiss Stephen Cook, Hashim Amla and Quinton de Kock, all of whom made centuries.
Boucher, who retired because of an eye injury in 2012 and is a summariser for BBC Test Match Special during the final Test, added: "He said he needed to learn the art of his trade and hence the chat with me.
"The signs are there, stick with him, a little bit of nurturing and he could be one of the greats."