By Dan Durkin–

(CBS) The responsibilities of an NFL general manager of are vast and varied, but the primary function is talent acquisition. Success or failure in that area underpins employability.

As Ryan Pace prepares to preside over the the Bears’ draft this weekend, which kicks off Thursday night and concludes Saturday, primary colors are at the forefront of his mind.

The Bears’ depth chart at Halas Hall has green magnets that signify team needs. An efficient 2016 free agent period peeled a few off the board, yet a green hue remains.

Teams typically categorize their existing talent using poker terms. Blue-chip players are considered perennial Pro Bowl difference-makers. By my assessment, the Bears have two blue chips in guard Kyle Long and receiver Alshon Jeffery. Red-chip players are dependable football players. The Bears have several of those.

Think back to the recent Super Bowl winners and the number of difference-makers they had on their rosters.

Pace needs to get the blues.

Since arriving in town in January 2015, Pace has been steadfast that the team’s path to sustained success is building through the draft.

Last year’s rookies made immediate contributions. Some red chips — safety Adrian Amos, defensive tackle Eddie Goldman and running back Jeremy Langford — have been added. Perhaps receiver Kevin White, who missed his rookie season due to shin surgery, becomes a blue. Certainly, that should be the expectation for a seventh overall selection.

This weekend’s draft marks the fourth opportunity for Pace to add talent to a roster whose two best players are holdovers from the previous regime. Thus, the pressure is on to deliver in his second draft overall and first with his hand-picked scouting department.

Clearly, Pace didn’t inherit an ideal situation. Then again, teams typically don’t push reset on a front office if everything is going well. The silver lining to having a talent-deficient roster is the Bears are truly in a position to take the best player available with most of their nine selections and certainly with those in the early rounds.

Conventional wisdom says the Bears should select a defensive player in the first round given their dearth of playmakers on that side of the ball. However, if there’s a potential blue-chip offensive player on the board — like Ohio State running back Ezekiel Elliott or Notre Dame left tackle Ronnie Stanley — the Bears would have to give serious consideration.

Successful general managers must strike a balance of fielding a competitive team in the short term while building and preparing for the future. Undoubtedly, the Bears have immediate, pressing needs. They need defenders who can impact an opponent’s passing game, be it someone along the front who can rush the passer or a defensive back who can make a play on the ball. However, Pace must resist the temptation to draft for need.

The Bears won a few hands in free agency but remain short-stacked at the NFC table. Pace has to adhere to his plan and acquire the best player available, which will deliver a successful draft this weekend that helps the Bears stack more chips.

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