The Ireland front row was suspended for two games by European Champions Cup organisers following an incident in the defeat by Toulon in France last Sunday.
Leinster have appealed, arguing that Healy was cited for one offence yet suspended for another.
As the appeal cannot be heard until after Saturday, he is free to play.
The 28-year-old could still miss the Pro12 meeting with Munster at Thomond Park on Sunday, 27 December.
"Leinster believe this is a failure to follow due process and is unfair to Cian Healy," the Irish province said.
Healy was handed the ban for dangerous play after being charged with striking Toulon hooker Guilhem Guirado with his knee during the 24-9 defeat in France.
The striking charge was found to be not proven but the incident was deemed to be foul play.
"As a written decision of the judicial officer is not available, it has not yet been possible to hear the player's appeal nor set a date for the appeal," said organisers European Professional Club Rugby.
"The player is therefore free to play until the outcome of his appeal."
Leinster prop Cian Healy is available for Saturday's game with Toulon after it was ruled he can play until his appeal against a two-game ban is heard.