On his weekly appearance on South Florida TV station WSVN Sunday night, agent Drew Rosenhaus appeared to solve the issue by stating that Roth had a groin strain.
But Coach Tony Sparano said Monday afternoon the same thing he had said Sunday, that Roth simply was "under the weather."
Sparano added that Roth had some blood work done to find out if there was a significant problem but everything checked out fine.
According to Sparano, Roth signed a statement before the conditioning test saying he had no injur or illness.
Sparano added that Roth told him -- not once, but twice -- that there was nothing with his groin, on which he had surgery in the offseason.
"I was told on two different occasions he was sick," Sparano said, saying the information came from Roth himself. "We're investigating it right now."
With Roth currently on the non-football injury list, Jason Taylor has been working as the strongside linebacker on the first-team defense.