The Miami Dolphins went from 4-12 in 2004 to 9-7 in 2005, making them one of the most improved teams in the NFL last season. Coach Nick Saban bolstered the Dolphins in his first season by focusing on defense and the running game, but the Dolphins now appear poised to create the biggest splash of a lively NFL off-season by making a major move for a new quarterback.

In all likelihood, Miami either will sign free agent Drew Brees of the San Diego Chargers or trade for Daunte Culpepper of the Minnesota Vikings. The question is, which one would be a better fit in Miami? The 27-year-old Brees and the 29-year-old Culpepper have four Pro Bowl appearances between them, and it is very rare for quarterbacks with Pro Bowl talent to be available in the prime of their careers. But both are also coming off major injuries that could affect the remainder of their careers, making it a significant gamble either way for the Dolphins.

Either quarterback would improve the Dolphins’ weak passing game, but Brees would be a much better fit in Miami. Saban, whose background is on the defensive side of the ball, delegates the offensive game planning to his assistants. Last year, Miami’s offensive coordinator was Scott Linehan, who had previously worked with Culpepper in Minnesota. But with Linehan now the head coach in St. Louis, everything about the Dolphins’ offensive coaching staff favors signing Brees.

Former Buffalo Bills head coach Mike Mularkey is now the Dolphins’ offensive coordinator, and Mularkey has always preferred dropback passers like Brees over scrambling quarterbacks like Culpepper. The Dolphins’ quarterbacks coach, Jason Garrett, is also much more similar in style and philosophy to Brees than he is to Culpepper. Garrett spent 12 years as an NFL backup (including four with the Giants) and he always excelled as a pocket passer rather than a scrambler.

Saban and general manager Randy Mueller met with Brees on Saturday and began contract negotiations with his agent. The New Orleans Saints will probably offer Brees more money than the Dolphins will, but Miami might still be a more attractive destination because the Dolphins appear ready to make a playoff run this year, while the Saints are entrenched in rebuilding mode.

Perhaps more important, the Saints are expected to choose a quarterback with the second overall pick in the April 29-30 draft, which would put Brees in the same situation he faced in San Diego after the Chargers spent a first-round pick on Philip Rivers two years ago. Brees wants to be the quarterback of the future, not a placeholder.

The only question about Brees is whether his throwing shoulder will heal sufficiently for him to practice Mularkey’s offense by the time training camp starts in July. Brees suffered a torn labrum and a damaged rotator cuff in his throwing shoulder in the final game of the 2005 season. He had surgery shortly after and has said publicly that he’ll be ready to throw when training camp starts. But the Dolphins’ medical staff could conclude the injury is more serious than Brees is letting on.

That could lead the Dolphins to turn instead to Culpepper, who played poorly last season before tearing three ligaments in his right knee in a game October 30. Although the injury to Culpepper’s knee is serious, especially for a player who relies on his running ability as much as Culpepper does, a bad knee won’t affect him as much as a bad throwing shoulder would affect Brees.

A year ago, when Culpepper was coming off a phenomenal season with 4,717 yards, 39 touchdowns, and 11 interceptions, the only thing more unthinkable than Minnesota wanting to trade him would have been the Vikings failing to find any interested trading partners. But the combination of the injury, his poor play in 2005 before he got hurt, and his bizarre behavior that has included severing ties with his agent and e-mailing the press to say he wants the Vikings to trade him have combined to make teams justifiably leery of Culpepper.

New Vikings head coach Brad Childress wants to get rid of Culpepper because he has seen what can happen when a prominent player is unhappy. Last year, as offensive coordinator of the Philadelphia Eagles, Childress witnessed receiver Terrell Owens disrupt the team and contribute to their fall from first place in the NFC East to last.

Miami’s starting quarterback last year, Gus Frerotte, is still on the roster, but Saban would like to relegate him to a backup role behind Culpepper or Brees. Because of the injury concerns with both players, Frerotte is a nice insurance policy, but last season was his first as a full-time starter since 1997, and he’s more suited to holding a clipboard on the sidelines than to taking snaps on the field. Still, if the Saints make Brees a huge offer and some other team makes a deal with the Vikings, the Dolphins could end up starting Frerotte.

The Dolphins could also be tempted to address their quarterback needs through the draft, especially because this year’s class includes two quarterbacks, USC’s Matt Leinart and Vanderbilt’s Jay Cutler, who appear to be good enough to start as rookies. (A third, Texas’s Vince Young, has great potential but probably needs a year to learn the pro game.) These quarterbacks, however, will be long gone by the time the Dolphins select in the middle of the first round. If Miami fails to secure either Brees or Culpepper, they will probably enter the season with Frerotte competing with one of the lesser free agent quarterbacks available, including Arizona’s Josh McCown, Cincinnati’s Jon Kitna, and Tampa Bay’s Brian Griese.

But like Frerotte, none of those quarterbacks has demonstrated an ability to be a consistent NFL starter. That’s why the Dolphins need to hit a home run. Culpepper would be an improvement, but Brees could make 2006 the year that the Dolphins dethrone the Patriots as kings of the AFC East.

Mr. Smith is a regular writer for FootballOutsiders.com.