BOSTON (CBS) — The Patriots added three more players to the reserve/COVID-19 list on Saturday, one day before the team is set to host the Denver Broncos at Gillette Stadium.

ESPN’s Field Yates reported that running back Sony Michel, guard Shaq Mason, and defensive end Derek Rivers were all placed on the list on Saturday.

READ MORE: Omicron COVID Variant Detected In Massachusetts Woman

That news comes one day after center James Ferentz was placed on the list, as well.

The Athletic’s Jeff Howe reported that Michel — who is on injured reserve — tested positive.

NFL Network’s Tom Pelissero noted that the NFL created stricter guidelines for placement on the COVID-19 list this week.

Michel remains the team’s leading rusher, despite his placement on injured reserve prior to the Patriots’ game against the Chiefs. The 25-year-old is not eligible to return from IR until Week 8.

READ MORE: Wind Gusts Across Eastern Mass. Projected To Be 50 MPH Or Higher On Monday Night

Mason, 27, was also inactive for the Chiefs game, as he was dealing with a calf injury. The right guard started the first three games of the season and missed just four games from 2016-19.

Rivers, 26, has been active for all four Patriots games this season, registering 1.5 sacks and three total tackles while taking a tick under 21 percent of the team’s defensive snaps.

The trio joins Ferentz and defensive lineman Byron Cowart on the reserve/COVID-19 list. Earlier in the week, quarterback Cam Newton, cornerback Stephon Gilmore, and practice squad defensive lineman Bill Murray were activated to the roster from the COVID-19 list after satisfying the NFL’s conditions for removal.

To help alleviate the losses on the active roster, the Patriots elevated four players from the practice squad for Sunday’s game.

Earlier on Saturday, the Broncos announced that their running back had tested positive for COVID-19 and did not make the trip to New England with the team.

MORE NEWS: Martin Richard Foundation Holds 4th Annual MR8K Race In Boston On Saturday

Despite the uptick in cases now involving both teams, all indications have pointed to the game being played as scheduled on Sunday at 1 p.m.