Per ESPN's Jeff Legwold, Broncos head coach Vic Fangio said Gordon was sent home and did not practice Friday because of an illness not related to COVID-19.
The game between the Broncos and Patriots at Gillette Stadium in Foxborough, Massachusetts, was originally scheduled to be played last weekend, but with the Patriots having multiple positive COVID-19 tests, it was postponed until Week 6.
Both quarterback Cam Newton and cornerback Stephon Gilmore were placed on the reserve/COVID-19 list for the Patriots in recent weeks, but both have since been activated and will be eligible to play Sunday.
There were some concerns regarding Sunday's game after the Patriots canceled their practice following another positive COVID-19 test Friday, but New England reopened its facility Saturday, according to ESPN's Mike Reiss.
In his first season with the Broncos, Gordon is off to a strong start. Through four games, he has rushed for 281 yards and three touchdowns while also catching 11 passes for 45 yards and one score.
The former Los Angeles Chargers star is a two-time Pro Bowler, but he is looking to reach the 1,000-yard rushing mark for only the second time in his six-year NFL career.
With Gordon out, Phillip Lindsay figures to take over as the starter Sunday. Lindsay has been out since suffering a toe injury in Week 1, but he is expected to play against New England, per Legwold.
Lindsay is among the best backups or complementary running backs in the game, as he rushed for over 1,000 yards in each of his first two NFL seasons and was named a Pro Bowler as a rookie in 2018.
Third-year man Royce Freeman, who has rushed for 30 yards on nine carries this season, also figures to be part of the Broncos' rushing attack.
Legwold reported quarterback Drew Lock is expected to be in the lineup for Denver as well after missing two games with a shoulder injury.
Lock's presence should give the 1-3 Broncos a better chance to hang with the 2-2 Patriots on the road, but New England remains the favorite.