The outbreak of the virus has struck down a few players over the past couple of weeks and even manager Sam Allardyce has suffered with the virus.
All appeared to be clearing up, but Allardyce confirmed that Roberts was being seen by a doctor.
"I'm okay now - I think we've only Jason Roberts," Allardyce said.
"There was another player suffering with it earlier in the week and Jason looks like it now, so we've left him at home and sent the doctor out to see him.
"The symptoms look very much like the general swine flu symptoms, so we will obviously go and get a full check on him."