MacGill was a star bowler in the Sixers' semi-final win over Hobart on Sunday night and will play against the Scorchers at the WACA Ground on Saturday night.
But, at 40, MacGill doesn't know if he can carry on into September's Champions League in India.
The former Test leg-spinner thinks the Sixers hold the edge over the Scorchers after last week's win at the SCG.
MacGill expects paceman Mitchell Starc to play after being named 12th man for Australia in this week's fourth Test.