A quick internet search seems to indicate that it’s a Tswana name, although the ‘c’ in the spelling suggests a non-Tswana origin, if it does indeed stand for the dental click found in Zulu and other languages. My guess for the original pronunciation would be [kaˈxisʰʊ dɪ(k)xaˈǀoi] based on the scant information I've been able to glean on Tswana (or with [χ] instead of [x]), but there are a few puzzling areas. […]
Also, although this is irrelevant to my question, how is the dental click [ǀ] usually approximated in an anglicized pronunciation? Or are words that have this sound that have found their way into English so rare that there is no usual approximation?
Being no expert on Tswana, I approached the BBC Pronunciation Unit. My former student Jo Kim, now working for the Unit, told me
Our own recommendation for this name is:(That is, kəˈhiːsəʊ dɪˈkækɔɪ.)
kuh-HEE-soh dick-ACK-oy (-h as in hot, -oh as in no, -oy as in boy, stressed syllables in upper case)
This is established anglicisation and the pronunciation given to us by Fulham FC Press Office, who consulted the player himself and wrangled up this English pronunciation between them. This was the anglicisation preferred by Mr. Dikgacoi according to the press office but I wasn't able to speak to the player himself.
A South African contact at the World Service told us that this name is Tswana. I spoke to a Tswana speaker on the phone (so I was unable to see anything!) but I certainly heard this: ka'xisʰo dik'xaǀoi
Wikipedia gives a quite different anglicization, namely diːˈxɑːtʃwɑː. Jo continued:
The 'dee-KHAA-chwaa' pronunciation was actually suggested to us by a colleague at ESPN [an American cable TV network, JCW] at one point as the “correct” pronunciation. I did hear audio of some Anglophone sports commentators based in Africa calling him by that pronunciation but I suspect that 'oi' being pronounced as 'waa' is a gallicization, perhaps due to the abundance of French names in South Africa.
So: in Tswana ka'xisʰo dik'xaǀoi; in English kəˈhiːsəʊ dɪˈkækɔɪ. (Americans would probably prefer kəˈhiːsoʊ dɪˈkɑːkɔɪ.)
Jongseong also wanted to know about the usual anglicization of clicks in borrowed words. I’ll look at that issue tomorrow.