The star underwent a procedure to repair a haemorrhaging nodule on his vocal cords on his 20th birthday last month (18Apr13), and is taking a break from his work with the group to recuperate.
His bandmate Tom Parker reveals they are not yet sure if the surgery worked, telling Britain's Daily Star Sunday, "He's doing all right. We won't know if it's been a success until he actually makes a recovery to start singing again."
Fellow singer Max George adds, "There is always a bit of concern there. He's only young so chances are he'll be Ok. But there's that underlying worry because it was a huge operation."
But MCGuiness is adamant the star will be a part of the line-up whatever the outcome of the operation: "He will always be part of the group whether he sings or not."