8,000 fans will attend two GAA matches in Croke Park on Saturday - in the stadium's biggest crowd in over a year.
They'll go to the Leinster senior hurling semi-final double-header, involving Dublin and Galway, and Kilkenny and Wexford.
Until now, the maximum capacity at games in the Republic of Ireland was 200.
Anthony Staines, a professor of health systems in DCU, says he wouldn't go to Saturday's games for fear of catching Covid.