Bush, McAllister present different tests

When Chicago plays New Orleans in the NFC championship game on Sunday, the best way for the Bears to handle the Saints’ Deuce McAllister and Reggie Bush is to not treat them both as running backs.

At 6 feet 1, 232 pounds, McAllister is a veteran power back with enough speed to wear down a defense. Whenever he’s on the field, the Saints’ running game is always a threat.

Bush, a 6-0, 205-pound rookie from USC, is more receiver than running back and New Orleans builds game plans around putting him in position to make big plays.

In order to slow down this diverse 1-2 punch, look for the Bears to make their defensive calls around fullback Mike Karney, who had a strong game for New Orleans in a 27-24 victory over Philadelphia last Saturday.

Karney, a 5-11, 258-pound bruiser, did not carry the ball or catch a pass against the Eagles, yet he was a difference-maker with his blocking. He often led the way for McAllister or Bush as the Saints finished with 208 yards and two rushing touchdowns against a tough Philadelphia defense.

When Karney is on the field, expect Chicago to play a base 4-3 defense -- four linemen, three linebackers -- looking to stop the run.

That should be the case even if Bush is on the field, because against the Eagles he carried 12 times for 52 yards and a touchdown.

But when the Saints are in need of key rushing yards, look for them to again turn to McAllister, who responded with 143 yards and a touchdown against Philadelphia. McAllister blasted off a 12-yard run the first time he carried against the Eagles, and he finished the game with a key first-down gain to keep a drive alive.

The more success McAllister and the Saints have running the ball, the easier they make things for Drew Brees, one of the league’s best quarterbacks when it comes to managing a game.

Against the Eagles, the Saints were able to keep their offense pretty simple -- mostly runs and high-percentage pass plays on first downs -- and that led to plenty of manageable third-down situations.

New Orleans converted six of 13 (46%) third downs and Brees, who passed for more than 300 yards in eight regular-season games, was coolly efficient if not spectacular. He passed for 243 yards, completing 20 of 32, and spread the ball among eight receivers.

New Orleans’ ground game figures to have an edge this week because Chicago’s defense has struggled recently. Playing without injured safety Mike Brown and defensive tackle Tommie Harris, the Bears gave up 108 rushing yards and two touchdowns to Seattle’s Shaun Alexander in a 27-24 Bears victory on Sunday.

In order to slow down the Saints’ running attack, the Bears are going to need big games from solid-tackling defensive backs, Charles Tillman, Chris Harris and Ricky Manning Jr.

But the more Chicago sells out to stop the run, that opens things up for Brees, who has the ability and the wide receivers to hurt the Bears with deep passes.

Summary: Middle linebacker Brian Urlacher, the focal point of Chicago’s defense, will be watched closely by Karney. Breaking into the Bears’ secondary will be key for the Saints’ running game, and if Karney can effectively neutralize Urlacher, McAllister and Bush could have productive running games.

lonnie.white@latimes.com