NEW ORLEANS, LA - SEPTEMBER 30: Quarterback Drew Brees #9 of the New Orleans Saints throws the ball in the first quarter against the Miami Dolphins at the Mercedes-Benz Superdome on September 30, 2013 in New Orleans, Louisiana. (Photo by Chris Graythen/Getty Images) New Orleans quarterback Drew Brees. (Chris Graythen/Getty Images)

By Steve Silverman

(CBS) — It looked so obvious in the first month of the season. Peyton Manning and the Denver Broncos were dominating the scoreboard every week.

If things continued to progress on the same path that they were on, Manning appeared to be a sure-fire, runaway Most Valuable Player award winner.

As the season turns for the home stretch, Manning is still the frontrunner for that award, but he is no longer open lengths ahead. Instead, he has been joined by some predictable candidates like Drew Brees and even Calvin Johnson, and a couple of outsiders who may have a chance to rally from behind and make a hard run at the award.

Peyton Manning, Denver Broncos – There’s still a great case to be made for Manning, even though Drew Brees has caught him in total yardage. Manning has completed 286-of-409 passes for 3,572 yards with a 34-8 TD-interception ratio. That last figure is Manning’s stand-out stat. Manning could still roar past the 50 touchdown mark this season.

However, nobody becomes an MVP candidate strictly because of the numbers. Manning has directed the Denver offense with a purpose and a consistency that nobody else can match. He works well with Eric Decker, Demaryius Thomas and Wes Welker, but you also get the feeling that none of those players wants to let him down

If Manning is going to lose the award, it’s likely going to be injuries that get him off track. Manning is playing with a sprained ankle and he has taken some hard falls when he has been hit this year. He gets rid of the ball quickly and doesn’t get sacked often, but when he does get hit, it’s usually a significant shot.

Drew Brees, New Orleans Saints – While it has taken him one more game to do it, Brees has passed Manning in yardage. That’s a significant achievement considering how brilliantly Manning started the season. Brees has completed 300-of-439 passes for 3,647 yards with 28 touchdowns and 8 interceptions.

Brees reads defenses as well as any quarterback in the league and he tends to make excellent decisions with the ball in his hand. Like Manning, he does not get overly excited in clutch situations and his teammates have maximum confidence in him. The Saints are not as explosive as they have been in past seasons, as tight end Jimmy Graham is the only receiver they have who intimidates his opponents.

His best hope of catching Manning will require the Saints to go no worse than 4-1 over his final five games. That would be a major achievement considering that the Saints will play the Carolina Panthers twice and the Seattle Seahawks once down the stretch.

Russell Wilson, Seattle Seahawks – On a statistical basis, Wilson doesn’t compare to Manning or Brees, but there is an intangible characteristic to Wilson’s game that gives him a huge edge. He’s tough, smart and athletic enough to make the big plays at key moments.

Wilson has completed 176-of-275 passes for 2,362 yards with an impressive 19-6 TD-interception ratio. Wilson also gets the job done on the ground with 72 carries for 409 yards and a touchdown. He also seems to avoid the big hits that other running quarterbacks like Robert Griffin III and Colin Kaepernick seem to take.

Wilson is perhaps the only quarterback out there who can compete with Manning and Tom Brady in terms of leadership. He is certainly the best of the young generation of quarterbacks in that category.

Cam Newton, Carolina Panthers – It’s nearly impossible to take your eyes off of Cam Newton when the Panthers are on the field because he is capable of a game-changing play on every snap. He has improved dramatically, but it has not manifested itself in his statistics. Newton has completed 189-of-299 passes for 2,179 yards with 16 touchdowns and 8 interceptions.

Newton is a brilliant runner, and his key fourth-quarter scramble was the key to Carolina’s Monday night home win over the New England Patriots. Newton has rushed for 328 yards and four touchdowns.

Newton has become a candidate because the Panthers have improved so much and appear to be a legitimate Super Bowl contender. However, his stats don’t measure up with the best and he needs to become a better short- to medium-range passer to have a legitimate chance.

Calvin Johnson, Detroit Lions – The only non-quarterback to have a serious chance – sorry LeSean McCoy and Marshawn Lynch – is the Lions’ sensational receiver.

Johnson has caught 59 passes for a league-best 1,083 yards with 11 touchdowns. He is averaging 120.3 receiving yards per game, and he has 16 receptions of 20 yards or more.

Johnson’s numbers are sensational, but it his size (6-5 and 241 pounds), strength, leaping ability and speed that give him a chance to catch nearly every ball thrown in his direction. His presence allows the inconsistent Lions to have a chance at the NFC North title.

Without him, they would be fighting the Minnesota Vikings to stay out of the NFC North cellar.

Steve Silverman is an award-winning writer, covering sports since 1980. Silverman was with Pro Football Weekly for 10 years and his byline has appeared in the Wall Street Journal, Playboy, NFL.com and The Sporting News. He is the author of four books, including Who’s Better, Who’s Best in Football — The Top 60 Players of All-Time. Follow him on Twitter (@profootballboy) and read more of his CBS Chicago columns here.