Town are set to be without ill midfield trio Cole Skuse, Jay Tabb and Teddy Bishop for Wednesday’s FA Cup third round replay against Southampton at Portman Road (KO 7.55pm).
Skuse missed Saturday’s 1-0 home defeat to Derby due to the virus, while Tabb was subbed in the second half along with Bishop.
Manager Mick McCarthy says they were all sent home from training earlier today: "Skusey came in this morning and he was sent home again. Tabby had to come off because of the effects of it, we sent him home as well this morning.
"And Teddy Bishop as well, so there’s a virus going around the place that’s laying one or two of them low. It’s very unlikely that they’ll be involved but I think the other 14 are OK.”
McCarthy says he was planning to make changes to his team in any case, as he did for the 1-1 draw at St Mary’s: "If you saw the team that we played at Southampton it’ll be similar to that, we had five or six changes and we competed very well.
"I am operating with probably 17 or 18 fit players and we’ve got Saturday-Wednesday-Saturday coming up, all big games, so I think it’s only right that I change some players.”
All three of the ill players are expected to be fine for Saturday's trip to Millwall.