(Undated) -- NFL action returns this weekend as teams head into Week Four. The Rams face a divisional opponent in the Cardinals as both teams enter Sunday with 3-and-oh records. Also locked in an NFC West battle is the 49ers, who take on the Seahawks at home. Each of them are trying to keep pace in what looks to be a tight divisional race. The Chargers and Raiders headline primetime action as they play one another on Monday night. Las Vegas sits a 3-and-oh, while Los Angeles enters 2-and-1.