The Vikings put running back Alexander Mattison on the reserve/COVID-19 protocol list Monday and claimed running back Wayne Gallman off waivers from Atlanta.
Special teams standout Dan Chisena and practice squad guard Kyle Hinton also went on the COVID-19 list for the Vikings. All three players tested positive for COVID-19, as did 34 other NFL players or practice squad members Monday.
Mattison, who has started three games this season as Dalvin Cook's backup, is unvaccinated and must sit out 10 days, so will miss Monday night's game in Chicago.
Linebacker Ryan Connelly was placed on injured reserve; he appeared to suffer a knee injury covering the second half kickoff in Thursday night's 36-28 victory over Pittsburgh.
Gallman's best game this season was against Dallas in Week 10, when he rushed for 55 yards on 15 carries. The Falcons waived him on Friday.
A fourth-round pick from Clemson in 2017 by the Giants, Gallman spent four seasons with New York, running for 682 yards in 2020. He signed with San Francisco as a free agent before this season but was cut by the 49ers and signed by Atlanta.
Gallman started 37 games at Clemson and ran for 3,429 yards and 34 touchdowns. He set a single-season school record with 1,527 yards in 2015.
Mattison, a third-year pro from Boise State, has 432 rushing yards this season on 116 carries, and 24 receptions for 183 yards. He has scored seven touchdowns.
Cook returned from a shoulder injury and ran for 205 yards in Thursday's game.
Kene Nwangwu has been the third running back for the Vikings, who are 6-7 this season. They return to practice Wednesday.
The Vikings have now had 17 players on the COVID-19 list since August.
The NFL issued a memo Monday requiring Tier 1 and Tier 2 employees to have a booster by Dec. 27. Tier 1 includes coaches and players, although requiring players to be vaccinated and get boosters would have to be negotiated with the NFLPA.