The Vikings' defensive line is missing future Hall of Famer Danielle Hunter, top free-agent signee Michael Pierce, potential Hunter replacement Yannick Ngakoue and free-agent departure Everson Griffen.

The linebacking crew is missing the highly-paid Anthony Barr.

The Vikings' top three cornerbacks from last year are gone, and three of their replacements — Cameron Dantzler, Mike Hughes and Holton Hill — have been missing because of injury.

Yet the Vikings will carry a three-game winning streak into Sunday's game at U.S. Bank Stadium against the Cowboys. This is a convenient time to credit Mike Zimmer and his staff for rallying the team. This is also the right time to recognize three players without whom Zimmer's coaching would not have mattered.

Middle linebacker Eric Kendricks and safeties Anthony Harris and Harrison Smith have controlled the middle of the field as their young teammates find their way.

All three are adept at reading offensive cues, blitzing and covering receivers all over the field. They have lately given Zimmer the ability to prevent big plays and trick opposing offenses.

Zimmer is known as an aggressive defensive coach, but without a star pass rusher, he has sometimes relied on a Cover-2 alignment, allowing Harris and Smith to play far off the line of scrimmage.

Tony Dungy and Monte Kiffin popularized the Cover-2 defense in Minnesota in the '90s. Leslie Frazier employed it while taking a mediocre Vikings team to the playoffs in 2012. All NFL coaches use it some of the time, but it is ideal for a team like the current Vikings, trying to protect young cornerbacks.

The Cover-2 requires a middle linebacker who can cover tight ends downfield. Kendricks did that Monday during the Vikings' 19-13 victory over the Bears. It also requires intelligent safeties like Smith and Harris with coverage skills.

While rewatching the game, I found these to be the plays that best illustrated the way Zimmer is using his three key defenders:

• Before the Bears' first offensive snap, Smith feinted toward the line, then dropped deep into a Cover-2 alignment with Harris. As Smith dropped, Harris began to creep forward. Chicago threw a receiver screen. Cornerback Kris Boyd took out the blocker and Harris dropped the receiver for no gain.

• On the next play, Smith dropped deep along the left hash mark while Harris remained closer to the line of scrimmage to his right. Foles, unhurried, threw high to receiver Anthony Miller over the middle. The ball glanced off his hands. Smith, playing deep and watching the play develop, caught the carom for an interception.

• The Bears faced third-and-goal later in the first. They went to a spread formation. Harris split wide to cover a tight end and Smith stayed close to the line on the right, faked a blitz and covered a back. Kendricks blitzed, creating a lane for Hercules Mata'afa to pressure Foles into an incompletion.

• The Bears faced third-and-10 late in the second quarter. Harris and Smith lined up deep, with Kendricks lined up as if ready to blitz. Harris covered Miller, a receiver, downfield, forcing an incompletion.

• On the Bears' first drive of the third quarter, Harris played deep while Smith feinted toward the line before dropping back. Bears receiver Allen Robinson broke open over the middle, but Smith broke forward and punched the ball away.

• On the Bears' next possession, they faced third-and-10. Smith lined up in coverage in the right slot, then looped inside on a blitz. Harris picked up the tight end who ran through the spot vacated by Smith, and Foles, under pressure, threw incomplete.

• On the Bears' last possession of the third, they again faced third-and-long. Smith lined up to the left of the defensive line while Harris dropped deep. Smith faked a blitz, then covered a tight end. With everyone covered, Foles took a sack.

Kendricks, Smith and Harris made the victory at Chicago possible. Sunday, they'll face an excellent group of Cowboys receivers. Their versatility and range will be required again.

Jim Souhan's podcast can be heard at TalkNorth.com. On Twitter: @SouhanStrib. • jsouhan@startribune.com