Williams has sat out of his side's last two Absa Premiership fixtures and last featured for Matsatsantsa in the CAF Confederation Cup final second-leg two weeks ago.
The 25-year-old shot-stopper's place has since been taken by former Kaizer Chiefs keeper Reyaad Pieterse, with new signing Thakasani Mbanjwa covering on the bench.
Coach Eric Tinkler will now have to make do without the services of his number one, who has been ruled out for six weeks.
"I'm out for the rest of the year, and only towards of the end of January I'll probably start training again," Williams confirms to KickOff.com.
"In the CAF final I hurt it [shoulder] when I slipped at one moment, and then the next day it popped out while I was at home, playing around."
The Port Elizabeth-born Bafana Bafana goalie also had the option of going under the knife, but decided otherwise.
"The option [to have surgery] was thrown out there, but today [Wednesday] I decided not to do the operation and we're going with the conservative option," he adds.