Redshirt freshman Daniel Jones will need to protect the ball better against Army after committing ... Third and goal: Duke football vs. Army A week after a disappointing 34-20 loss to Virginia, Duke looks to move to 3-3 Saturday against Army in its final nonconference game. The Blue Devils dominated the Black Knights 44-3 on the road last season, but Army has been much improved this year with a 3-1 record so far. Here are three keys to Saturday's contest:Stop the OptionArmy utilizes a triple-option attack that has been especially deadly so far this season, averaging more than 36 points per game. Sophomore running back Andy Davidson and junior quarterback Ahmad Bradshaw have combined to average more than 170 rushing yards per game this season along with eight rushing touchdowns. Duke had little trouble stopping the option last year, forcing seven fumbles in its 44-3 win, but will need to remain disciplined defensively to contain the formidable rushing attack. The Blue Devils will need big games from linebackers Joe Giles-Harris and Ben Humphreys to help slow down the Black Knights' offense.Protect the FootballDuke did an abysmal job protecting the football last week against Virginia with six turnovers, including a game-sealing fumble in its own end zone with four minutes left. The Blue Devils' giveaways handed the Cavaliers several short fields to work with, and Virginia wound up scoring 21 points off turnovers. Duke has lost the most turnovers in the nation this year, and redshirt freshman quarterback Daniel Jones will have to be more careful against an opportunistic Army defense that already has six interceptions this season.Mind the WeatherHurricane Matthew is sweeping through the Southeast this weekend, bringing a forecast of heavy rain and high winds to Durham Saturday. The wet conditions may make throwing the ball difficult, forcing Duke to rely more on its run game, which has struggled so far this season with just 3.9 yards per carry. But redshirt senior running back Jela Duncan may return to action this week after missing the Virginia game and should feature as a big part of the Blue Devil attack. The weather could also have an impact on special teams, which was shaky for Duke early in the year, though freshman kicker A.J. Reed converted both of his field goal attempts last week. Head coach David Cutcliffe may not want to send the kicking unit out to try many field goals in the harsh conditions Saturday.