Start 'Em & Sit 'Em is the ultimate look at the weekly NFL matchups and how they'll affect your fantasy football team. Sleeper alert features an under-the-radar player who could produce good numbers. Owners beware features a regular fantasy starter who could fail to meet expectations based on the strength of his opponent. Obvious fantasy starters like Aaron Rodgers and Arian Foster will not be featured in this column. For your final lineup decisions, check our lineup rankings.
Start of the week
Cardinals defense at Miami Dolphins: Ladies and gentlemen, the Cardinals defense is a legitimate fantasy option this season. Ranked second in points at the position on NFL.com after three games, this unit has held Tom Brady and Michael Vick in check over the last two weeks. As a result, shutting down rookie Ryan Tannehill and the punchless Dolphins offense shouldn't be an issue.
Giants defense at Philadelphia Eagles: What team have defenses scored the most fantasy points against in the first three games of the season, you ask? Well, it's the Eagles. Between Vick's turnovers and a questionable offensive line, defenses have feasted on the Birds in 2012. That makes the G-Men, who will be well rested after playing last Thursday, a very attractive fantasy option.
Falcons defense vs. Carolina Panthers: You might not realize it, but the Falcons are in the top five in fantasy points among defenses heading into Week 4. This week they'll host Cam Newton and the Panthers. In the first three weeks, defenses have scored the ninth-most fantasy points when facing this struggling offense. Surprisingly, the Falcons are still available in 70 percent of NFL.com leagues.
Sleeper alert - Seahawks defense at St. Louis Rams: Aside from what was a very questionable call at the end of the game, last Monday's win over the Packers proved just how good the Seahawks are on the defensive side of the football. This unit, which is still available in plenty of fantasy leagues, should dominate Sam Bradford and the Rams. If you need a defense, look for the 'Hawks.
Sit of the week
Bills defense vs. New England Patriots: The Bills have been impressive over the last two weeks, scoring a combined 27 fantasy points in games against the Chiefs and Browns. However, their next matchup, a home game against Tom Brady and the Patriots, is far less than favorable. In fact, defensive units facing the P-Men have scored the third-fewest fantasy points after three weeks.
Eagles defense vs. New York Giants: After scoring a solid 14 fantasy points in Week 1, the Eagles have combined to post a mere nine over the last two games. That includes just three in a loss to the Cardinals. Next on the schedule is a date with the Giants, who haven't been a defensive whipping boy. In fact, defenses have scored the sixth-fewest fantasy points against Eli Manning's crew.
Lions defense vs. Minnesota Vikings: Last season, the Lions were one of the top-scoring defenses in fantasy football. That was then and this is now, however. After three weeks, only three defenses have scored fewer fantasy points than these Motor City cats. Defenses going up against the Vikings have averaged a mere five fantasy points per game, so the Lions are a questionable option.
Owners beware - Jets defense vs. San Francisco 49ers: As if the loss of CB Darrelle Revis wasn't enough to make the Jets less attractive in fantasy circles, now comes a matchup against the Niners at MetLife Stadium. This unit should be motivated to produce at a high level after being beaten in Minnesota last week, and Alex Smith doesn't make many mistakes. Keep the Men in Green benched.