Baden Kerr, Waisake Naholo, Bryn Hall and Kane Barrett have been added to the Blues squad for the 2013 and 2014 Super Rugby seasons.
Hall, a 20-year-old half-back, and 21-year-old winger Naholo have gained international honours for the New Zealand Under-20s, while versatile back-five forward Barrett captained NZ Secondary Schools.
The quartet will now be looking to make the step up to the next level after their inclusion in Sir John Kirwan's squad.
"As we continue to secure the squad we want for next season, we are thrilled to include these four players," said Kirwan.
"They fit the criteria for the types of players we are looking for in their respective positions as well as how they will mesh with those already in the squad."
No.8 Peter Saili, who has made 45 appearances for the Auckland franchise has been handed a new 12-month deal.