By Dan Durkin–

(CBS) Even prior to the Bears’ trade of Brandon Marshall, wide receiver was a need position for them. Last season, their primary pass catchers were all of similar athletic profiles: tall with long arms who won matchups with leverage rather than speed. Without a deep threat, opposing defenses played split-safety looks and over the year, they crept closer and closer to the line of scrimmage as there was no threat over the top.

The Bears brought in Eddie Royal in free agency, who gives them a shifty slot receiver, but they still lack long speed.

Today we take a look at the most polished pass receiver in the 2015 class: Alabama’s Amari Cooper.

WR Amari Cooper (6-foot-1, 211 pounds, 20, Alabama)

40-yard dash: 4.35-4.38
Vertical: 34”
Arm: 31 1/2”

Bio: Cooper arrived in Tuscaloosa as a four-star wide receiver and top-50 recruit and made an immediate impact for the Crimson Tide.

As a freshman, Cooper appeared in all 14 games, starting the last nine and leading Alabama with 59 receptions for 1,000 yards and a school-record 11 touchdowns. Those numbers earned Cooper consensus first-team All-American honors. Cooper’s numbers slid his sophomore season as coverages started to roll his way and he battled through foot and toe injuries. He finished with 45 receptions for a team-high 736 yards and four touchdowns.

Cooper’s junior year in 2014 was prolific. He led the nation with 124 receptions and his 1,727 yards and 16 touchdowns were both the second-highest totals across the land. He was a consensus first-team All-American and won the Fred Biletnikoff Award, which is given to the nation’s top receiver. He was also a finalist for the Heisman Trophy.

In all, Cooper made 30 starts at Alabama and scored 31 touchdowns. He decided to forgo his senior season of eligibility and enters the draft as arguably the top prospect of a loaded class.

Pro outlook: Cooper’s combine 40 times were recently adjusted to the 4.35-4.38 range from 4.42, and his speed shows up on film. He loses very little speed when decelerating at the top of his route stem to set up a cornerback, and his acceleration coming out of his breaks is second to none. He plays with a second gear to take the top off of a defense on deep routes.

Cooper is a smooth route runner who was targeted at all depths (short, intermediate, deep) and showed toughness in his willingness and ability to work over the middle of the field. He’s a natural hands catcher, which allowed him to snare and hold onto passes in traffic.

Cooper has shown lapses in concentration. He dropped several catchable passes that would’ve gone for big gains. He stands to put on some upper-body strength to win jams with strength, instead of relying solely on footwork. More upper-body strength will also enable him to be more of a factor as a down-field blocker in the run game.

Bears wide receivers coach Mike Groh recruited Cooper and coached him during the 2012 season.

Draft projection: Cooper is the most productive wide receiver prospect in this class and should be a top-five selection.

Dan Durkin covers the Bears for CBSChicago.com and is a frequent contributor to 670 The Score. Follow him on Twitter at @djdurkin.