A day before rookies take the field in Eagan for the start of a three-day rookie minicamp, the Vikings front office began signing its 12-man draft class.

Tight end Irv Smith Jr., the 50th-overall pick last weekend out of Alabama, was the first of eight draft picks to sign a four-year rookie contract on Thursday. All NFL rookie contracts pay based on draft slot, so Smith Jr.'s deal will be worth about $5.5 million through the 2022 season. He's expected to count just over $1 million against this year's salary cap.

(Here's the Vikings' outlook in fitting its draft class under the salary cap.)

The Vikings also signed third-round running back Alexander Mattison, fourth-round guard Dru Samia, fifth-round linebacker Cameron Smith, two sixth-round picks in tackle Oli Udoh and safety Marcus Epps and two seventh-round receivers in Olabisi Johnson and Dillon Mitchell.

Only four draft picks — first-round center Garrett Bradbury, sixth-round defensive tackle Armon Watts, seventh-round cornerback Kris Boyd and seventh-round long snapper Austin Cutting — remain unsigned.

Rookies without the protection of a signed contract typically sign an injury waiver before participating in this weekend's three-day minicamp. Due to the boilerplate nature of rookie contracts, draft classes typically get signed quickly. However, squabbles over offset language in the contract (meaning if the player is cut, his remaining guaranteed money can be offset by what is earned elsewhere) can delay the process. The Vikings' top pick last year, cornerback Mike Hughes, didn't sign until the middle of July.