Heat confirmed on Friday both Khawaja and Labuschagne would face the Melbourne Stars in the first match of the tournament on December 7.
The pair are also some chance to play in the Heat’s second game on December 9 in Adelaide, the same day the Test squad is due to enter camp in Perth.
A decision on that could ultimately lie with the players with the Heat not wanting to compromise the duo’s preparations ahead of the first Test against Pakistan on December 14.
“We are delighted to confirm Usman and Marnus’s availability for the opening night of the Big Bash League,” Brisbane Heat CEO Terry Svenson said.
“Both players have had incredible years across the World Test Championship and Ashes plus Australia’s recent World Cup victory, so it’s wonderful our home fans can see them in action to kick the season off.
“Both Usman and Marnus are passionate about playing for Heat and I’m sure our fans will be looking forward to seeing them both in teal before the Test summer begins.”
The call to clear the pair to play the start of the BBL comes after the Heat lost four players to PM’s XI selection. Michael Neser, Matt Renshaw, Jimmy Peirson and Nathan McSweeney were all this week confirmed as being part of the PM’s squad, for the four-day match starting December 6 in Canberra.
AAP understands selections for the PM’s game had caused some tension between Cricket Australia and the clubs, who did not want to lose their marquee players to the tour match.
Sixers will also lose Todd Murphy due to PM’s XI selection against Melbourne Renegades, with no other club impacted at this stage.