Eight in the Box: Must-keep free agents

Welcome to "Eight in the Box," a new NFL Nation feature that will appear each Friday during the offseason. This week's topic: Which free agent is essential for each team to keep from its 2012 roster?

Baltimore Ravens: Quarterback Joe Flacco. A no-brainer, as Flacco’s historic playoff run vaulted him into the upper tier of NFL QBs, and a record-setting contract could follow. Assuming the two sides strike a deal (a likely scenario), the next question becomes how it impacts the Ravens’ ability to retain other key free agents such as outside linebacker Paul Kruger, safety Ed Reed and linebacker Dannell Ellerbe.

Cincinnati Bengals: Defensive end Michael Johnson. Defensive coordinator Mike Zimmer’s scheme manufactures pressure, but the presence of Johnson (11.5 sacks) and Geno Atkins (12.5 sacks) allowed Cincinnati’s front seven to wreak havoc on opposing passers in 2012. Johnson, 26, has rare physical gifts and is likely to earn a big contract.

Cleveland Browns: Place-kicker Phil Dawson. The list of Browns free agents is uninspiring at best, and the franchise is in the midst of an overhaul. Dawson, 38, was spectacular again in 2012, the second consecutive year he played under the franchise tag. For an offense entering a new system in 2013, a reliable kicker is needed.

Pittsburgh Steelers: Cornerback Keenan Lewis. Wide receiver Mike Wallace is the biggest name among the Steelers’ free agents, but he’s out of place in their current offensive system. It’s Wallace’s high school teammate, Lewis, who must be re-signed. Quality young corners are not easy to find, and Lewis, who was second in the NFL with 23 pass breakups in 2012, fits the bill.

Field Yates is a contributor to ESPN Boston.com and ESPN Insider.

Jamison Hensley will return to the AFC North blog next week.