( CNN ) -- AC/DC founder Malcolm Young wo n't be returning to the group , the band has announced . The group 's new album , `` Rock or Bust , '' does not include Young . It will be released December 2 , with a single , `` Play Ball , '' due to make its debut Saturday during the TBS postseason baseball campaign . ( TBS , like CNN , is a unit of Time Warner . ) In April , the band revealed that Young was struggling with an undisclosed ailment . A press release said the illness was the reason he was unable to return . `` Unfortunately , due to the nature of Malcolm 's condition , he will not be returning to the band , '' the statement said . `` AC/DC will undertake a world tour in support of 'Rock or Bust ' in 2015 . Stevie Young , nephew of founding members Angus and Malcolm Young , plays rhythm guitar on 'Rock or Bust ' and will accompany the band on tour . '' AC/DC 's Malcolm Young ill , 'taking a break ' from band . The band has n't disclosed the nature of Malcolm Young 's illness , but one musician told an Australian radio station in April that the situation was `` serious . '' Mark Gable told Australia 's ABC Radio that Young `` is sick . ... It 's not just that he is unwell , it 's that it is quite serious . '' Gable 's remarks were reported at the time in The Sydney Morning Herald . In July , lead singer Brian Johnson told Classic Rock magazine that Young was in the hospital . `` We miss Malcolm obviously . He 's a fighter . He 's in hospital but he 's a fighter . We 've got our fingers crossed that he 'll get strong again , '' Johnson told the magazine . AC/DC is one of the biggest-selling bands in music history with more than 70 million albums sold in the U.S. alone , according to the Recording Industry Association of America .
Group founder Young wo n't be returning , band says . Young has been suffering from an undisclosed illness . His nephew , AC/DC , will take over , band says . AC/DC 's new album is due out in July .