The Scotland international has strained a thigh muscle but is expected to return for Sunday's Scottish Cup quarter-final with Motherwell.
His place in the side will be taken by David Robertson, while Danny Swanson will continue in midfield.
Paul Dixon returns after a virus, but striker Jon Daly remains out following a hernia operation along with knee injury victim Garry Kenneth.
Long-term victims Darren Dods (knee) and Scott Severin (ankle) are also absent.
Source: PA
Source: PA