Sinkevicius' nomination has already been approved by the government and President Gitanas Nauseda and is yet to be endorsed by the national parliament and the European Parliament.
The Seimas is expected to vote on his candidature on Thursday.
The 28-year-old member of the ruling Lithuanian Farmers and Greens Union has served as economy and innovation minister since 2017.
His career includes positions at the state-run airport operator Lietuvos Oro Uostai (Lithuanian Airports), Lietuvos Pastas (Lithuanian Post) and the government's foreign investment promotion agency Invest Lithuania.
Sinkevicius has also previously worked at the Washington-based Center for European Policy Analysis and has done a traineeship at the Lithuanian embassy to the United States.
The new European Commission will take office in November. Vytenis Povilas Andriukaitis, Lithuania's outgoing European commissioner, is in charge of health and food safety.