The Vikings agreed to re-sign an eighth free agent on Thursday.
Offensive lineman Austin Schlottmann agreed to terms, a league source confirmed, keeping some depth at center and guard. Schlottmann started four games last season for center Garrett Bradbury, who also agreed to return on a three-year deal this week.
Schlottmann, 27, joined the Vikings last year on a one-year contract after spending four seasons with the Broncos as a 2018 undrafted signee. He suffered a broken fibula in the Jan. 1 loss at Green Bay.
The Vikings have also retained six other internal free agents: running back Alexander Mattison, kicker Greg Joseph, long snapper Andrew DePaola, quarterback Nick Mullens, tight end Ben Ellefson and outside linebacker Kenny Willekes.
Seven former Vikings players remain unsigned in free agency: receiver Adam Thielen, receiver Bisi Johnson, tight end Irv Smith Jr., cornerback Chandon Sullivan, cornerback Duke Shelley, cornerback Kris Boyd and tackle Oli Udoh.