Mathews has missed the last seven quarters of football after suffering a high ankle sprain. Reports are that he’s practiced fully this week and has an excellent chance to get the starting nod in week four.

He should be thrust back into a heavy workload against a porous (to say the least) Arizona rush defense, ranking 31st in the NFL.

San Diego will be anxious to establish the ground game after tossing the ball 53 times for 455 yards last week in a come back effort at Seattle.

If healthy and effective, Mathews will garner the majority of carries, despite the solid play of Mike Tolbert in his stead. However, he must hold onto the rock! A fumble a game is not something to be proud of.

Backs are always PPR threats for the screen happy Chargers.

RB Sit – Peyton Hillis, Cleveland Browns

It’s official. The Hillis secret is out. After his demolition of the vaunted Ravens defense, Hillis is one of the hottest commodities in fantasy circles.

There’s a lot to like: power, nose for the goal line and great hands, but let’s not crown him the next Mike Alstott just yet.

At 250 pounds, Hillis has always displayed tremendous versatility at the fullback spot, but has never been a full time ball carrier.  Over time, his weaknesses WILL be exposed i.e. lack of speed (4.7), quickness and change of direction.

The Bengals will surely eliminate the Browns bread and butter, forcing Seneca Wallace or Jake Delhomme to beat them through the air. While the Bengals front seven is banged up, the game plan should be sufficient to limit Hillis’ productivity.

QB Start – Vince Young, Tennessee Titans

Young has been the least active quarterback in the NFL through three weeks, averaging a touch over 14 pass attempts per game.

With Chris Johnson being stuffed, the tide began to turn in the second half last week against the Giants. Young aired it out 12 times in the second stanza alone, including a 4/4 48-yard touchdown drive.

Against a shored up Denver run defense, the Titans might be forced to open things up once again. Despite being a week healthier, this is the same Broncos secondary that allowed David Garrard to look like an NFL QB (16/21 and three TD).

Young has yet to break a big run in 2010, but is due to explode. There will always be risk starting an inconsistent thrower in a running scheme, but the potential for reward is significant in this spot.

QB Sit – Donovan McNabb, Washington Redskins

After ten seasons, Donovan McNabb will hit Lincoln Financial Field as a visitor for the first time.

Despite the total absence of a number two receiving threat, he’s racked up 278 passing yards per game in the early going. But true efficiency presents itself in the red zone, where McNabb has yet to connect on a TD pass (two overall).

Quite frankly, the Redskins don’t possess the running game or downfield presence to act as a pressure release against the Philadelphia blitz. It’s a good bet McNabb will be running for his life with regularity against a defense that has already sacked the QB 12 times. The Eagles are also holding opposing signal callers to 53.8% accuracy.

From both the perspective of physical and verbal treachery, this could get ugly.

WR Start – Johnny Knox, Chicago Bears

Averaging 21.1 yards per reception, Knox continues to emerge as one of the leagues legitimate deep threats.

With the Bears suddenly boasting weapons all over the field, Knox has more space to utilize his primary weapon, speed. And he has the perfect quarterback in place to take advantage of those downfield shots. He’s not seeing an overabundance of targets, but when he does he makes them count.

The Giants number four ranking against the pass is bordering on false advertising, having faced Matt Moore, Vince Young and a run happy Colts team in the opening three weeks. If they don’t get pressure on Cutler, Knox could have a field day matched up one on one against a struggling Corey Webster.

Weather conditions for Sunday night look ideal for the passing game with minimal wind impact.

WR Sit – Mike Sims-Walker, Jacksonville Jaguars

I hate to be overly harsh on David Garrard, but as long as he’s the starting quarterback, it’s tough to use any Jacksonville wide receiver. He’s been that putrid.

In two games and three quarters with Garrard behind center, Sims-Walker has caught eight balls for 104 yards and one score (in garbage time).  These underwhelming numbers include an empty stat line in week one.

The Jaguars have always found success running the football against Indianapolis, but throwing the ball is a different story. In four career games against the Colts, Sims-Walker has eight receptions for 90 yards. This sit recommendation is not a knock on MSW, but his best chance to accumulate stats is in a blowout against the prevent defense.

TE Start – Daniel Fells, St. Louis Rams

With Billy Bajema and Michael Hoomanawanui out with injuries, Fells is the man at tight end for the Rams.

He saw four targets last week, catching three balls for 22 yards and a touchdown.

Often given poor protection by his offensive line, TE’s and RB’s have been popular outlets for rookie quarterback Sam Bradford.

The Seahawks were blitz happy in passing situations last week, but when they didn’t get there receivers were running open all over the field. Fells should find some plus matchups to do some damage in the red zone.

TE Sit – Owen Daniels, Houston Texans

Daniels has essentially been a non-factor since returning from November ACL surgery. Normally one of the league’s most agile tight end’s, Daniels lacks any real burst at the moment.

If Andre Johnson sits, look for a heavy dose of Arian Foster and the run game. Daniels will likely see more targets, but he is not ready to make game changing contributions.

Sit him until he proves otherwise. The Raiders have not faced a top tier TE this season, allowing only a one-yard touchdown to Bo Scaife.

*UPDATE – according to Rotoworld.com Owen Daniels was held out of Thursday’s practice with a hamstring injury.

Written by Adam Ganeles exclusively for TheFantasyFix.com. Check back weekly for Adam's NFL Sit 'Em, Start 'Em .