Impressive on loan at Portman Road at the end of last season, Welsh midfielder Williams moved from Crystal Palace on Monday and made an instant impact when netting the equaliser at Sheffield Wednesday.
Having come on as a substitute, Williams was then subbed himself due to injury but should be fit for the trip to the City Ground on Sunday.
"He had a bit of a groin (problem) although he shouldn’t have, as he had a warm-up at half-time and I primed him that he was going on in the second half," said Ipswich manager Mick McCarthy.
"But we have got Nottingham Forest on Sunday and then a two-week international break so he will be fine."