If the Eagles and McNabb ever part, there are some interesting scenarios

Donovan McNabb needed a 16-game season of relative health. So did the Eagles.

That's a lot to ask for a quarterback coming off a knee reconstruction, but -- like Carson Palmer -- McNabb trains hard and is a consummate pro. Injuries, however, have been his downfall of late.

Over the past four seasons, McNabb missed 20 games because of injuries, and, although no one would like to admit it, there are still unhealed emotional scars in the locker room from the Terrell Owens experience.

With his 12-year, $108 million contract under review in the next 13 months, McNabb might be in his last season in Philadelphia. Emotionally, Andy Reid might have a tough time letting him go, but there is a hard business decision that has to be made with regard to McNabb.

At 31, McNabb is at the crossroads of his Eagles career. With McNabb's contract running out in 2009, Philadelphia has to extend him or trade him.

The temptation of trading him and the impact of the 2008 playoff race will be the focus of the 2008 offseason. If I were the Eagles, I'd keep McNabb like the Packers kept Brett Favre. Quarterbacks are too hard to find, and McNabb has lived up to his high draft selection in 1999. He has been to four NFC title games and the Super Bowl and he has made average receivers good, but sometimes being sentimental isn't good business.

Networks don't start bidding on 2008 games until late January, but one thing is clear: The team that acquires McNabb becomes an automatic playoff contender and a top TV attraction. What's becoming clearer each year in an age of diminished returns from free agency is this: The fastest way to improve the fortunes of a franchise is to enrich the quarterback position.

Go back to the 2006 season. The easiest thing to figure out was that the acquisitions of Drew Brees and Steve McNair could translate into trips to the playoffs. Health questions made them available, but the Saints and Ravens gambled and won.

The combination of Brees and coach Sean Payton made the Saints the Cinderella team of the NFC in 2006. McNair helped the Ravens win 13 games last season.

As many millions of dollars are spent in free agency or in trade acquisition, two teams that improved this offseason were the two teams that made successful quarterback moves. Tampa Bay thought Jeff Garcia could manage the running and passing games for Jon Gruden, and the Bucs are on the verge of clinching the NFC South. Houston coach Gary Kubiak took a chance on Matt Schaub, and he has responded with a 66.5 completion percentage and a respectable 5-6 start for the Texans.

The teams expected to be the most active in the quarterback market next season are the Falcons, Ravens, Bears and Vikings. Atlanta coach Bobby Petrino probably will want to draft a quarterback to address his needs, so let's explore the impact McNabb could have on the other three teams.

The McNabb-to-Chicago rumblings have been around for years. McNabb grew up in Chicago. His return would be as exciting to Bears fans as the sight of Mike Ditka.

McNabb would be like family in Chicago. Rex Grossman's contract runs out this season, and there probably are only two ways he'll be back. If Grossman has a strong finish, he could persuade management to give him a long-term deal. Figuring that won't happen, the Bears would re-sign him to a short-term deal only if they can't find the future quarterback of their choice.

I'd place Chicago third in the McNabb sweepstakes. General manager Jerry Angelo prefers building through the draft, so he won't be the most aggressive in offering trade value to the Eagles. Plus, less costly options could become available. What if the Jets cut Chad Pennington or give him away cheaply?
Pennington lacks the strong arm, but he's smart and he takes teams to the playoff.

The more natural fit would be in Minnesota. Brad Childress coached McNabb before coming to the Vikings, and the quarterback would be the missing piece in both saving Childress' job and turning Minnesota into a playoff team. On top of that, the Vikings are having some difficulty selling out their games. Acquire McNabb, and tickets might be in demand.

Making the right quarterback move could boost a team's scoring average by a touchdown per game, and that could mean the difference between making the playoffs or staying home.

Last year, the Bucs averaged 13.3 points a game with the mess they had at quarterback. With Garcia in charge, the Bucs are averaging 19.4 points a game, and they are doing it with aging receivers and a backup running back because of Carnell (Cadillac) Williams' season-ending knee injury. Schaub has taken the Texans from an offense scoring 16.7 points per game to a 22.1-ppg attack.

The Vikings are a McNabb away from challenging for the NFC North title. Plus, he'd be the perfect mentor to Tarvaris Jackson, whom Childress believes in -- even seeing flashes of McNabb.

The Vikings have a well-paid, talented offensive line. They have the best backfield duo in football: Adrian Peterson and Chester Taylor. They have a defense that is impossible to run on and forces turnovers.

Putting McNabb on the Vikings would make Minnesota one of the hot teams in 2008. The Vikings are averaging 21.4 points a game, but a part of that is the 63 points scored on returns. The offense is averaging about 15 points a game. McNabb would turn Minnesota into a legitimate 22-ppg or better offense and fill the Metrodome.

Quarterback value only increased in 2007.

Officials aren't calling the close holding penalties, so quarterback performance has skyrocketed. Tom Brady can break numerous quarterback records. Completion percentages are higher than ever. The league average is 61.9 percent. That's 2 percent better than 2005 and 2006 and 1.2 percent better than the NFL record set in 2002.

Twenty teams have starting quarterbacks completing at least 60 percent of their passes, and given the extra offseason to fully recover from his knee surgery and work on his mechanics, McNabb should watch his 59.8 completion percentage get back into the 60s.

The Eagles aren't dumb. Quite to the contrary, Philadelphia management is one of the best in football at projecting ahead and making moves for the future.

Eagles management knows it has to get the right value for McNabb, and his recent history with injuries might make it tough to get a first-round pick or more. It also knows giving McNabb to an NFC team could elevate that squad's playoff chances at the Eagles' expense.

That's where Baltimore becomes an interesting option. The Ravens thought McNair could squeeze three more years out of his skills, but he hit the wall physically this year. That happens. Kyle Boller has a year left on his deal after signing an extension, but he's clearly not the answer to the Ravens' offensive problems.

The Schaub trade last season set the market for a potential McNabb deal. Even if the Eagles can't get a first-rounder or more, they certainly should get the equivalent of a second- and third-rounder. That could be paid out in a second- or third-rounder in 2008 or a second-round selection in 2008 and a second-rounder in 2009. If you're the Ravens or the Vikings, you'd make that move without blinking, and if you're the Eagles, you'd prefer putting McNabb in the AFC for obvious competitive reasons.

McNabb should stay an Eagle, but if this Eagle does land elsewhere, he will be the biggest piece in the 2008 offseason puzzle.

John Clayton, a member of the Pro Football Hall of Fame writers' wing, is a senior writer for ESPN.com.