Mayo manager John Maughan will have to plan without Peadar Gardiner for this Sunday's Bank of Ireland Connacht semi-final against Roscommon.
Gardiner has not recovered from ligament damage sustained in a recent club match.
Gary Mullins, Conor Moran, Alan Roche and Pat Kelly are now in contention for the two half-back positions alongside James Nallen.
"He has ligament damage to the knee, which is worse than what we thought it was," said Maughan.
"Initially we thought a week or two might heal it but it's going to take longer."
