Laing missed the draw with Ross County after suffering a thigh knock against Hamilton the previous weekend and manager Ian Baraclough admitted he faced a battle to make the game.
Motherwell have no fresh injury problems.
Defender Mark Connolly has an outside chance of rejoining Kilmarnock boss Gary Locke’s squad.
The Irishman broke his collarbone at Inverness at the end of February but has now resumed training.
Midfielder Jamie Hamill could also make his first Killie appearance since Valentine’s Day after recovering from ankle surgery, while striker Michael Ngoo (ankle) remains on the sidelines.
Victory for Motherwell will condemn St Mirren to relegation.