Scouting the Cowboys/Colts game put me in mind of a few key individual matchups.
Marvin Harrison vs. Terence Newman
The ability of Newman to handle Harrison could have a domino effect on the rest of our defense. If Newman can handle him man-to-man without requiring a lot of safety help, then Dallas is free to use their safeties in other areas. Newman needs to take away Harrison as a major weapon for Manning. He probably won't shut him down completely - Harrison is too good for that - but if he can contain him, then Dallas can cheat one safety to play over the top of Reggie Wayne and help out the inconsistent Anthony Henry. We could also use Roy Williams closer to the line to help with the run and stop the screens and underneath routes by the RB's and TE's.
DeMarcus Ware vs. Tarik Glenn
With Greg Ellis out for the season, the time is now for DeMarcus Ware to start taking over games with his athletic skill. The Cowboys can't afford to live on the blitz against Manning, we aren't a good blitzing team and Manning will eat up a poor blitz. DeMarcus Ware needs to beat Tarik Glenn by himself and get some pressure on Manning and disrupt the Colts backfield.
Dwight Freeney vs. Flozell Adams
Adams has traditionally struggled with speed rushers, especially guys who have more pass rush moves than just around the edge. Freeney can beat you with his strength and drive, he has a relentless motor, and he will set you up for the speed rush. When Adams has a bad game, it's usually against guys like Freeney. Dallas can't afford to have Tony Romo under too much duress, no matter how well he's handled it so far. A couple of mistakes on a rushed throw or from throwing off-balance, or a fumble or lost yards on sacks could be just enough for the Colts to win.
Tony Romo vs. Peyton Manning
This isn't a traditional individual matchup, they aren't actually on the field against each other. But in some ways the QB's of a game are always matched-up against each other. 3-4 defenses have given Manning problems in the past. New England for a few years was one he couldn't solve, and lately San Diego and Pittsburgh have managed to beat the Colts. If Manning struggles against another 3-4, Dallas could get itself a victory. On the other side, Romo has to play well and he needs to play error-free. He doesn't need to out-produce Manning because Dallas will rely on its running game a lot, but he does need to play well, and do it in a huge game. This will be a real test this early in his career.
Dallas run game vs. Colts run defense
The Cowboys will run the ball all day if the Colts are soft up the middle. The Cowboys want to control the clock and give their defense plenty of rest while keeping Manning off the field. The Colts haven't been able to stop teams from running all year and the Cowboys have one of the better run games in the league. If Romo can be efficient in the passing game and keep the Colts defense honest, Dallas should be able to run their way to victory.
Dallas WR's vs. CB Jason David
Look for the Cowboys to attack corner Jason David. Buffalo WR Lee Evans had some success early against David last week, but the Bills didn't stick with any kind of passing attack to finish the game. Dallas will throw the ball and have the skill players to make it work, so expect them to pick on David.
TE Dallas Clark vs. ???
Newman will cover Harrison, and Anthony Henry plus a safety will cover Reggie Wayne, but who will Dallas send out to cover Dallas? Coach Parcells could choose to stay in his base defense and use a safety/linebacker combination to do the job, but that favors Clark. They could run out 3rd CB Aaron Glenn like they did against 3-wide sets last week in Arizona, but that weakens the run defense. Against a team like the Colts, you probably would rather have them run than pass, so Glenn might be the answer.
Dallas linebackers vs. Colts running backs/tight ends
The Colts will run draws, they will dump it into the flats, and they will run screens to RB's or TE's. The Dallas linebackers will be counted on to recognize these plays and to make solid tackles before they become big plays. Joseph Addai and Dominic Rhodes are very capable backs, the Cowboys linebackers will be counted on to do a lot of things well in this game.
Payton Manning vs. Keith Davis/Pat Watkins
Whenever Dallas loses, the FS is usually involved in a couple of the big plays that go against Dallas. Manning will surely take his chances against them several times in the game.
Dallas Cowboys vs. the referees
The Cowboys can't commit penalties like they have been recently. To beat a team like Indy, you need to play error-free ball.