The stand-off has yet to play for Glasgow since signing from Northampton last summer.
Savala is joined by centre Johnny Ventisei, who made his debut last weekend, having previously been Scotland's U20 captain.
Glasgow Hawks' scrum-half Callum Reidy also joins Franco Smith's squad, after providing cover for the Warriors since the Six Nations.
Warriors return to Champions Cup action when Bulls visit Scotstoun on Saturday in the round of 16. Glasgow captain Kyle Steyn has an outside chance of playing. The winger has recovered from a stress fracture and is due to return to training and should be available to play either this week or next.