Five intriguing free-agent prospects

Albert Haynesworth is going to dominate the headlines the next few days as free agency approaches. The Tennessee Titans are scrambling to re-sign him but he could break the bank with a potential $15-16 million-a-year deal. Still, free agency isn't all about the headlines. There are subplots and surprises. While most of the attention is on Haynesworth, Ray Lewis and Kurt Warner, here are five key story lines on players who might slip behind the headlines but have a major impact on free agency.

1. Dallas Cowboys defensive end Chris Canty: It's hard to find ends to play in the 3-4 defense, and that's why the Cowboys' strategy of letting him hit the market is a little surprising. With Bill Parcells as head coach in 2005, the Cowboys turned around their defense when they drafted DeMarcus Ware, Marcus Spears, Kevin Burnett, Canty and Jay Ratliff. Canty outperformed Spears and fit nicely in the 3-4 scheme. With more teams experimenting with the 3-4, Canty will be in demand because he's 304 pounds and can play the 2-gap at the line of scrimmage. Ratliff, who made the Pro Bowl at nose tackle, fears he might have to move to end if Canty leaves.

2. Baltimore Ravens center Jason Brown: With more teams going to the 3-4, centers need to be bigger to handle the nose tackles who line up directly in front of them. The Ravens have been trying to re-sign Brown for months, but he could break the bank in free agency. Losing Brown would hurt the Ravens because they are in a division with big nose tackles, including Casey Hampton in Pittsburgh and Shaun Rogers in Cleveland. Whoever lands Brown will have an insurance policy in case teams in its division shift heavily to 3-4 schemes. The Ravens have to worry about a team such as the Miami Dolphins wooing Brown. Parcells wants the Dolphins to get bigger at center in an AFC East that has 3-4 defenses and big nose tackles on the New York Jets and the New England Patriots. Brown should end up being the highest-paid center in football by the end of the week.

3. Miami Dolphins inside linebacker Channing Crowder: He has developed into a tackling machine in Miami. He had 113 tackles last season and has averaged 94.5 tackles a season over the past four years. He's done that even though he's never started 16 full games in a season. Talks between the Dolphins and Crowder have stalled and there is a decent chance he could hit the market. If he does, expect a game of musical chairs at inside linebacker. Ray Lewis, Bart Scott, Zach Thomas, Kevin Burnett and others could be moving around to different teams. The only knock on Crowder is not coming up with big plays. He's had only 1½ sacks and hasn't forced a fumble during his four-year career. Still, he's a big player in this free-agent market.

4. Dallas Cowboys nose tackle Tank Johnson: Life has been quiet for Tank since his turbulent departure from the Chicago Bears. He moved to Dallas and learned how to be a nose tackle, which should enhance his value. Johnson could add beef to a 4-3 team wishing to stop the run better or he could anchor a 3-4 defense at the nose. The league is looking for bigger defensive linemen. Tank is 6-foot-3 and 305 pounds, and he lives up to his name -- he's hard to move. The Cowboys will let him hit free agency. Johnson has cleaned up his personal life, and now he can help clean up the problems on a team's run defense.

5. Pittsburgh Steelers quarterback Byron Leftwich: It seems like only yesterday Leftwich was the franchise quarterback for the Jacksonville Jaguars. The Steelers couldn't believe Leftwich and Daunte Culpepper were on the street when they were looking for a veteran backup quarterback after Charlie Batch was hurt last season. Leftwich accepted a minimum salary deal and gave the Steelers maximum insurance in case anything happened to Ben Roethlisberger. At the moment, Leftwich doesn't appear to be in the front line of quarterback moves. The Minnesota Vikings are trading for Houston Texans backup Sage Rosenfels. The Tampa Bay Buccaneers have
Luke McCown holding the starting job until they figure things out. The Jets, for the moment, have Kellen Clemens facing off against Brett Ratliff in training camp, but Leftwich would fit nicely into their scheme. The Lions are going with Culpepper and might draft Matthew Stafford. The Kansas City Chiefs are still trying to figure out their quarterback strategy. But Leftwich is only 29 and he's good enough to be a starter.

John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.