After quietly rushing his way to 1,081 yards with Dominic Rhodes to help carry the load, Joseph Addai will be asked to shoulder the bulk of the Colts' rushing duties in 2007. Michael Hickey/WireImage.com

Challenge No. 3: Find out if Joseph Addai can carry the load

With Dominic Rhodes departing during free agency, Addai gets the opportunity to be the feature back in '07. Though he flashed all of the skills to be an outstanding starter during his rookie campaign, there are questions about his ability to handle more than 300 carries during a 16-game regular season. Based on his size, overall skills and production in a limited role, Addai appears to be capable of taking on the expanded role. His 1,000 rushing yards led all rookie backs last season and the three games he produced in the playoffs in which he gained more than 100 yards of total offense showed that he was capable of being the workhorse in pressure situations. The Colts obviously feel that he is ready to take on the task. With limited depth behind him, the gamble on Addai's durability and effectiveness will be one of the key factors to the Colts' success.

Jacksonville Jaguars

Challenge No. 1: Break in two young starters at safety

With the departures of Deon Grant and Donovin Darius, the Jaguars enter the season with two relatively inexperienced players at the safety position. First-round pick Reggie Nelson and third-year pro Gerald Sensabaugh are slated to man the deep positions in the secondary. Without a dependable veteran backup on the roster, though, Nelson and Sensabaugh will log plenty of preseason snaps to try to develop the trust and accountability necessary to play in the back.

Challenge No. 2: Build an explosive offense

Despite having several talented players on the offensive side of the ball, the Jaguars have struggled scoring points consistently during the Jack Del Rio era. New offensive coordinator Dirk Koetter has been given the task of coming up with an explosive offense to complement the Jaguars' championship-caliber defense. His track record at Boise State and Arizona State is impressive, but several college coaches have failed to find the same success on the pro level. How he builds his attack around the strengths of his best players is more critical than the system or scheme he chooses to run. With Fred Taylor, Maurice Jones-Drew and Byron Leftwich as their best offensive weapons, you can expect a strong running game complemented by a vertical passing attack using multiple tight end formations. Though the Jaguars lack a legitimate No. 1 receiver, they have three athletic players (Reggie Williams, Ernest Wilford and Matt Jones) who can create mismatches down the field. Second-year tight end Marcedes Lewis has the skills to be a playmaker in the red zone, and veteran Jermaine Wiggins is a dependable option in the middle. There is no doubt that the Jaguars have enough talent to be a top offense, but putting it all together will be the key.

Challenge No. 3: Shed the underachiever label

The Jaguars' 8-8 record last season was clearly disappointing for a team of their talent. Having knocked off five playoff teams last season, the Jaguars cost themselves dearly by not being able to win the games they were supposed to win. Key losses to Washington, Houston and Buffalo kept the team out of the playoffs. Heading into '07 with high expectations, they have to find a way to grow from good to great. Youth and inexperience can't be used as excuses anymore. There is no magic formula to achieving this goal, but since their defense is their backbone, getting that unit to dominate on a weekly basis would be a good start. Though they only gave up an average of 16.2 points a game (2nd in the league), they allowed more than 24 points in six of their eight losses. For a defense that has the talent to be considered among the league's best, they have to dominate all opponents, not just a few of them. Expect Del Rio to place the responsibility on the defense to lead the Jaguars into the playoffs.