On April 26, 2013, Aaron Rodgers signed a five-year, $110 million contract that made him the highest-paid player in the league. At the time, the salary cap was at $123 million.

Since then, the cap has risen $20.28 million to $143.28 million and no one has topped that deal. Revenues in the league are increasing at a $1 billion-a-year rate. The cap is increasing $10 million a year. So how can the cap can go up 16.4 percent without anyone topping the $22 million-a-year mark?

At least eight top quarterbacks have signed deals since Rodgers agreed to one with the Green Bay Packers. But with Rodgers being considered the best or one of the best quarterbacks in the league, no one has had enough leverage to top him.

The market is changing enough that the Rodgers' contract eventually will be topped. There is an outside chance Russell Wilson could get a deal this week that tops Rodgers'. Wilson is hoping for $25 million a year. Unfortunately for him and others, that market won't open until next year, as I wrote yesterday in analyzing his situation.

Beyond Wilson, who is next? Well, Eli Manning, Philip Rivers and Andrew Luck have the chance to top Rodgers, but there are obstacles. This starts the debate. Is it better to sign now, when teams have the leverage to keep their quarterbacks under the $22 million level, or is it better to wait until next year?

Here's a breakdown.

Eli Manning, New York Giants

The Giants are trying to reach a contract extension with Manning (34) before the start of the regular season. Manning doesn't have a worry in the world. Pay him now or pay him later. Manning is in position to win either way. If he signs now, he would have to take something close to the four-year, $87.4 million contract signed by the Pittsburgh Steelers' Ben Roethlisberger.

Although it's possible the Giants might offer a little more than that to reach an agreement, it's hard to imagine Manning getting too much more than $22 million a year if he signed this year. Roethlisberger and Manning entered the league at the same time in 2004. Each has two Super Bowl rings. Their résumés and accomplishments are pretty close.

If he waits until next year, Manning could take the quarterback market into the $24 million-a-year range. The team isn't going to let Manning hit free agency, so it will give him the franchise tag if necessary. With a $19.75 million cap number this year, Manning's non-exclusive 2016 franchise number would be $23.7 million. If they have to franchise him in 2017, his number would be $28.44 million.

Blending those numbers gives him the leverage to ask for $25 million a year on a long-term deal, knowing the worst-case scenario is averaging $26.07 million for the next two seasons. With a $17.5 million salary this year, Manning doesn't have to rush into anything.

If San Diego can't reach a long-term deal with Philip Rivers, the exclusive franchise tag might be the way to go. Donald Miralle/Getty Images

Philip Rivers, San Diego Chargers

The debate for Rivers (33) is about location more than money. With a big family, Rivers may not want to move to Los Angeles if the Chargers bolt San Diego. Of course, such a position could give him some leverage. In many ways, it probably benefits Rivers to wait until next year. He's going to make $15.75 million this year and could likely get $23 million or more per year on a long-term deal if he's willing to stay in a Chargers uniform. His cap number would be $20.9 million in 2016 and $25.08 million in 2017 as a non-exclusive franchise player. Those numbers would increase if Manning gets more than that after the season.

If you're the Chargers, though, you can't risk having Rivers available as a non-exclusive franchise player. Some team might be willing to gamble two first-round picks to acquire him if the Chargers elect not to match a signed tender. That puts the Chargers in the position to give him the exclusive franchise tag so no other team can make him an offer. Currently, the exclusive tag is valued at $25 million, but the number will come down if Drew Brees, Roethlisberger and Joe Flacco reduce their cap numbers next year to free up room for their teams.

Andrew Luck, Indianapolis Colts

He plays in a retractable dome, but the sky is the limit for what Luck can make. With 33 regular-season wins and two division titles behind him, the 25-year-old Luck should be able to negotiate a deal worth at least $24 million a year.

The Colts have elected to let him play out this season at $3.4 million, the final year of his rookie contract. He's on the books for a $16.155 million salary for next year after the Colts exercise the fifth-year option in his first-round contract. Like Peyton Manning was before him, Luck is the face, arm, heart and soul of the franchise. The Colts are extremely lucky to have him and know they have to pay him.

Timing was everything for Bradford. As the first pick in the 2010 draft, Bradford was the financial benefactor of the old collective bargaining agreement that rewarded prospects who hadn't been on the field better than most of the veterans around the NFL. He received a six-year, $78 million contract before he played a down of pro football. Injuries spoiled his career in St. Louis, so the Rams opted to trade him to Philadelphia for a pretty good return.

A healthy and productive 2015 would likely ensure another nice pay day for Sam Bradford. Bill Streicher/USA TODAY Sports

As long as Bradford stays healthy and does well in Chip Kelly's offense, he should be fine financially. At the very least, he should be eligible for a $3 million-a-year raise. What he has to do is prove he's good enough to be a starting quarterback, which, for the one time rookie of the year, mostly means staying on the field. The market for a good starting quarterback is at least $16 million a year. Sixteen quarterbacks are currently making at least $16 million a year. Wilson, Rivers and Luck will be taking that number to 19. If Bradford does well, he will be the 20th or 21st depending on what happens to Nick Foles.

The Rams like Foles enough to have preliminary extension talks. Foles is in the same position as Bradford. All he has to do is prove he's a quality starter to approach the $16 million-a-year scale. Like Bradford, the better Foles does, the higher his stock will climb.

What could help Foles is the team around him. The Rams are the youngest team in football and are loaded with talented draft choices acquired over the past three years. If Foles is able to take a young team to the playoffs it could push his number from $16 million to Ryan Tannehill's $19.25 million-a-year range. The debate for the Rams is whether they should sign him now before his price goes up.