The Costa Rican has bronchitis.
That report prompted Everton fans to fear the worst about the Costa Rican's health.
But rather than something more sinister it is clear that he simply has a chest infection - similar to the one which recently left Gareth Barry stricken at the club.
Roberto Martinez has confirmed as much today and the player himself also made it clear he was just suffering with a bout of bronchitis on his official Twitter account last night:
Oviedo has been in good form for the club this campaign. He usurped Leighton Baines, who has been struggling with an ankle problem, as the number one left-back for the Toffees after thriving in the position.
Roberto Martinez has now confirmed that the player went to hospital for treatment on his chest problem but could still be ready to face Chelsea in the FA Cup this weekend.
Regardless of whether he can face Chelsea or not Everton fans will just hope he can recover fully from the illness and return when fully fit.