The team announced on Monday that Stroll had been injured in a cycling accident while training, and won't be able to take part in the three-day test.
Formula 2 champion Drugovich has been thus called up and will get an unexpected opportunity to try the new AMR23.
Fernando Alonso will drive the car on Thursday afternoon, but the team says it has not yet firmed up its schedule for the remaining two days of the test.
Aston Martin's other reserve driver, Stoffel Vandoorne, is committed to the Formula E event which takes place in Cape Town on Saturday.
The Sakhir track mileage will give Drugovich a chance to get up to speed, which will be useful in case he's required to race the car in Bahrain, or indeed at any stage this year.
It will also help him with correlation with the team's simulator, in which the Brazilian will conduct extensive running over the course of the season.
Drugovich had his first experience with Aston Martin when he drove the AMR22 in FP1 in Abu Dhabi last year, and he also stayed on for the young driver test at the same venue.
Speaking about his incident, Stroll said: "I've had an unfortunate accident whilst training on my bike in preparation for the season. I am determined to get back in the car and I am excited about the season ahead with the team. I am motivated to bounce back from this setback as quickly as possible."
The team added that Stroll "is however expecting a quick recovery and return to driving duties. His fitness to return to the cockpit will be assessed daily and the team will issue an update ahead of the Bahrain GP."
Assuming Stroll is fit enough to be able to take part in the race weekend he will in on the back foot having missed a vital one and half days of testing.
