They will always be linked. It started on draft day 2004 when Eli Manning and Philip Rivers were traded for each other. It continues on Sunday when both young quarterbacks lead their teams to the conference championship games. And frankly, it will be that way until the end of their careers. Each quarterback will ultimately be judged not simply on how well he performed, but on how well he played in comparison to the other.

Most of the focus will be on the other two quarterbacks who are playing Sunday. Green Bay’s Brett Favre holds all of the meaningful career records for passers. He’s a two-time league MVP and trying to earn his third trip to the Super Bowl. New England’s Tom Brady just had the best season ever by a quarterback, throwing 50 touchdown passes and leading the Patriots to a perfect 16–0 record in the regular season. He’s trying to win his fourth Super Bowl in just his seventh pro season. Brady and Favre are probably among the best four or five quarterbacks to ever play the game.

Those guys are known quantities, but both Manning and Rivers remain enigmatic. Clearly, neither quarterback has lived up to the lofty expectations their teams have had for them. Manning has spent three full seasons as the Giants’ starter and went to the playoffs in each of those seasons. Rivers has two years at the Chargers’ helm and two trips to the postseason. At first glance, you have to consider each player’s career to have been pretty successful so far.

Nevertheless, questions remain about each quarterback. As recently as a month ago, many pundits were ready to conclude that Manning was just an average quarterback. I was definitely among them. In four seasons, he’d shown only momentary flashes of brilliance. Most of the rest of the time he was inconsistent, and his inability or unwillingness to be more vocal led some to conclude that he was never going to emerge as a great leader. A new Manning has emerged over the last month, the one we thought we’d never see. With newfound confidence, he’s playing the best football of his career. Still, unless Manning leads the Giants to a Super Bowl win this year, these concerns will reemerge during the offseason.

The questions abound in San Diego, as well. Rivers has a strong arm but a funky delivery that leads to poor mechanics. He also lacks poise at times. That’s illustrated by his tendency to leave the pocket too quickly when he’s under pressure, but also by his occasional loss of composure. On two separate occasions during last weekend’s playoff game in Indianapolis, Rivers got into a shouting match with Colts fans in the stands. That sort of behavior raises questions about his maturity and his judgment.

In the weeks leading up to the 2004 draft, I talked to scouts and coaches to get their opinion on the quarterbacks at the top of the draft board. Some liked Rivers’s arm strength. Others thought Manning’s pedigree gave him more upside. Still, others thought Ben Roethlisberger was the best player of the three despite coming from a smaller football program. There was no consensus, and I couldn’t find anyone who felt emphatically that one of these kids was significantly better than the others. Except, of course, for Giants general manager Ernie Accorsi.

Much of the pressure weighing on Manning’s shoulders stems from the way he got to New York. It started when he announced he wouldn’t play for the Chargers if they drafted him, then multiplied when the Giants paid a steep price to acquire him. The Giants gave up three draft choices in the deal. The Chargers used two of those picks to select Pro Bowl kicker Nate Kaeding and linebacker Shawne Merriman, who led the league in sacks in 2006. Unless Manning proves to be a significantly better quarterback than Rivers over the long haul, the trade — and Manning himself — will go down in team history as a huge disappointment.

Both Rivers and Manning enter the weekend as prohibitive underdogs. Manning will have to outplay Favre in Lambeau Field, while Rivers has to beat a team that seems destined to go undefeated. The odds are that both young quarterbacks will be starting their offseason on Sunday night.

Ultimately, the question for both of them isn’t whether they’re ready to become champions now, but whether they ever will. In advancing to the conference title game, are we seeing each take the next big step in their path toward their goal, or is this simply the peak of their careers? Is this their first big game or their last?

Rivers has more young stars around him than Manning does. LaDainian Tomlinson is the best running back of his generation. Merriman may be the best linebacker playing today, and Antonio Gates is one of the two or three best tight ends in the game. But in the long run, my money’s on Eli Manning, not just to outplay Rivers, but to justify the faith that Accorsi and the Giants placed in him. He’ll never be at the same level as his brother Peyton, but I’m convinced he will win championships. Manning has great mechanics, ideal size, and his decision making will improve with experience. He’ll post better numbers in the next few years, as young receivers Steve Smith and Sinorice Moss move into starting roles. And let’s face it, I’d rather have a quarterback who’s calm than one who starts yelling at folks in the stands.

sl@seanlahman.com