Philadelphia Eagles quarterback Jalen Hurts is battling an illness that may sideline him for Monday night’s game against the Seattle Seahawks.

Hurts did not practice on Friday because of an illness. He was downgraded to questionable on Sunday, and ESPN’s Adam Schefter reports that the star quarterback’s condition worsened over the weekend. Hurts will still travel to Seattle, but he will do so separately from the rest of the team.

Hurts is coming off a poor performance in Philadelphia’s 33-13 loss to the Dallas Cowboys last week. The Eagles also looked outclassed in a 42-19 loss to the San Francisco 49ers the week before, so they have not fared well against the NFC’s best teams.

If Hurts cannot play on Monday, backup Marcus Mariota would get the start. The 10-3 Eagles are still tied for the best record in football, but they would face an uphill battle in a tough road game if Hurts sits.