Alfa 2021 reserve driver Kubica has already driven his C41 car on the Barcelona track in a shakedown event ahead of pre-season testing.
Last month Kubica also won the opening race of the 2021 European Le Mans Series at the same venue, sharing an LMP2 ORECA 07-Gibson Louis Deletraz and Yifei Ye for the WRT team.
Kubica will pick up Kimi Raikkonen’s car for FP1 on Friday, which will follow Antonio Giovinazzi giving way to Callum Ilott in the same session for last weekend’s Portuguese GP.
The Tuesday and Wednesday following the Spanish GP, Alfa will join Alpine and Red Bull to complete testing on Pirelli’s 18-inch tires – although Alpine will only race on test opening day.
“I can’t wait to get back in the car this Friday and next week,” said Kubica.
“Having last driven the C41 in Barcelona in February, I can’t wait to see how far the car has come since – both in terms of upgrades and the team’s understanding of the whole.
“Driving a Formula 1 car is always a special experience and I look forward to contributing to the team’s efforts in the midfield battle.
“Plus, driving the new 18-inch tires will be a new experience and the first taste of the new world that will emerge next year.
Alfa team boss Fred Vasseur added: “It’s great to have Robert back in the car for his first practice session of the season and for the Barcelona test.
“Every time he gets in the car is invaluable for us to tap into his vast experience and have a different perspective on the C41.
“His technical feedback will also be crucial in his races with the 2022 tires.
“We’re in the middle of a very close fight in midfield and every contribution from our talented pool of drivers can be the secret weapon that gives us that edge to move forward.