"Just spoke to the doctor operation went well, Thanks for the support I've truly been blessed," tweeted Williams.
The 27-year-old revealed the news a day after arriving from Japan, where he picked up the injury playing for the Panasonic Wild Knights.
Williams smashed his shoulder into the turf after making a tackle in Panasonic's 23-20 win over Kintetsu Liners.
With Japanese rugby on a five-week break, the New Zealand heavyweight champion initially flew to Sydney to prepare for his bout against 44-year-old Botha.
But it was rumoured that the dual rugby league and union international was also poised to formally sign a contract to return to rugby league with the Sydney Roosters.
Instead, Williams went straight to the NRL club's headquarters at Moore Park to undergo scans on an injury that could threaten or at least delay his high-profile switch back to the code after walking out on the Bulldogs in 2008.
Reports on Tuesday night suggested Williams was set to be out of action for at least two months.
The injury puts in jeopardy his return to the Wild Knights, where he is contracted until the end of January.
His Panasonic club told Reuters on Wednesday they were discussing a rehabilitation schedule for Williams but were not sure when he would return to Japan.
"It's not been decided where and what kind of rehab programme he will undergo," team manager Seigo Ikeda said.
"We want to work out those details quickly obviously."
While his mooted deal with the Roosters might still eventuate, the untimely injury has the potential to further complicate negotiations that have been bubbling away for months.
In July, Williams said he would quit the All Blacks to fulfil a handshake agreement made several years ago to return to rugby league in the NRL in 2013.
- AAP
