With the NFL free-agent negotiating period having opened at noon Saturday, it's timely to take a closer look at our ESPN NFL free-agent tracker.

This year, ESPN NFL analyst Bill Polian served as our "general manager" for the tracker, assigning letter grades to each player available. The grading scale is tied to a salary value: Polian believes an 'A' player should receive a contract with an annual value of at least $6 million, while a player with a 'B' should receive between $2-6 million per season.

That's when Polian's 'B-minus' grade for Buffalo Bills safety Jairus Byrd caught our eye.

By next week, Byrd could become the highest paid safety in the NFL, as he's expected to fetch a deal worth at least $9 million on the open market. That represents a wide gap between Polian's valuation and what Byrd could actually receive, so we asked the former Bills general manager about his take on Byrd.

Polian said the salary ranges assigned to the letter grades can eventually change based on market spending, but noted that his grade of Byrd wouldn't be affected.

"He's a speed-deficient safety," Polian said. "Safeties don't get faster as the years go on."

Byrd is the third-ranked safety on Polian's list, behind Antoine Bethea (who received an 'A') and Chris Clemons (who received a 'B').