Gustav Malja will make return to GP2 for the remaining two rounds of the 2015 season at Bahrain and Abu Dhabi with the Rapax team.
The 20-year-old will replace Robert Visoiu because of an injury to the Romanian driver preventing him from racing.
Andrea Bergamini, Rapax CEO said in a statement: "We were sad to hear about the injury occurred to Robert and we wish him a prompt return on-track."
"In the two final events of the season at Bahrain and Abu Dhabi we will have the chance to welcome a young rookie like Gustav Malja, who aims to consolidate his experience aboard the GP2 Series Dallara.
"Malja will rely on the support of both the team and his team-mate Sirotkin, as the Russian will be battling for third place in the driver classification," he added.
Swede Malja made his GP2 debut earlier this year with Trident at Spa-Francorchamps and scored his first point, finishing 10th in the feature race.
Rapax sits fifth in the teams' championship with 141 points, while Sirotkin is fourth in the drivers' standings chasing third place man Rio Haryanto, the pair separated by only five points.