The band announced last week that they had been forced to cancel a series of concerts after McDaid (42) suffered “a serious problem with his neck”.
It was the latest injury problem to plague the band after guitarist Nathan Connnolly sustained a hand injury.
The Friends star shared a picture with Johnny, who was wearing a neck brace, on Instagram. “Happy to be taking care of my man….I’M HIS NUMBER ONE FAN!” Cox wrote on Instagram.