The 31-year-old is still committed to representing his country in one-day and Twenty20 internationals and is hopeful that exploratorysurgery will enable him to do so in the future.
However, the exploratorysurgery has ruled out any chance of that happening and Welbeck is now not expected to play again until March, which is roughly the time his team-mate Fraizer Campbell is expected to return after a six-month injury lay-off.
But with the deal now dead in the water he will have to look elsewhere as he seeks to cover Bent and Danny Welbeck who is out for eight weeks after exploratory knee surgery, with Fraizer Campbell also a long-term absentee.
The hope was that the dislocation Williams suffered after being thrown to the ground by Frans Steyn had not caused too much damage, and that the surgery would just be exploratory.