Aaron Rodgers. Image source: Michael Heisel via Flickr.

Despite the scandals over the past year, the NFL remains America's most popular sports league. In fact, as of 2014, approximately 32% of Americans called pro football their favorite sport, which is twice the number who favor baseball. As a result, the NFL continues to cash in on its large fan base, as each year the league brings in more than $10 billion in revenue and earns an estimated $1 billion in profit.

Just under half of the league's revenue is spent on player salaries, with each team's salary cap set at $143.28 million for the 2015 season -- a $10 million jump from the previous year. However, it is the league's unique salary cap system that actually makes it tricky to peg its highest-paid player each year. To demonstrate that, here's a look at the highest paid player in the NFL, using three different definitions.

Average annual value
With an average annual contract value of $22 million, Green Bay Packers' quarterback Aaron Rodgers is by most accounts the highest-paid player in the NFL. It's a value that is derived from Rodgers' contract, which calls for him to be paid $110 million over five seasons. However, due to the structure of his contract, it's a bit more complicated than that, as he's not necessarily the highest-paid player each year.

The reason for this is because the contract includes a signing bonus, roster and workout bonuses, and a fluctuating base salary. That base salary is what has held Rodgers' actual earnings down, as it was just $900,000 last year and will only improve to $1 million for 2015. However, that base isn't his only earnings: In 2015 he will also get a $10.1 million roster bonus, a $500,000 workout bonus, and $6.5 million of his signing bonus. Add it all up, and Rodgers' salary cap hit is $18.25 million for 2015, which isn't the highest in the league.

Base salary
With a base salary that lately has been around $1 million, Aaron Rodgers is nowhere near the top of the list for highest base salary in the NFL. It's a distinction that last year belonged to Bears' quarterback Jay Cutler as a result of his signing a seven-year, $126.7 million contract, which provided Cutler a base salary of $17.5 million. However, due to his contract's structure, his base salary will actually drop to $15.5 million for the 2015 season, which will result in Cutler slipping in the rankings. Given where things stand right now, New Orleans Saints' quarterback Drew Brees is currently projected to have the top base salary for the 2015 season at $18.75 million.

Salary cap hit
The final definition of the highest-paid player in the NFL is the player who has the greatest financial impact on his team's salary cap. For the 2014 season, that distinction belonged to Defensive Tackle Ndamukong Suh when he was a member of the Detroit Lions. His cap hit last year was $22.4 million, which was nearly twice his base salary of $12.6 million. That said, he won't hold that distinction for the 2015 season, as the free-agent contract he signed with the Miami Dolphins starts out with a low base salary of less than $1 million and a total cap hit of $6.1 million. As a result, New Orleans Saints' quarterback Drew Brees is expected to have the largest 2015 cap hit for his club at $26.4 million, due in part to the fact he'll have the highest base salary for the upcoming season. However, Suh is expected to retake the crown for the 2016 season, as his cap hit is expected to skyrocket to an NFL-leading $28.6 million, unless of course someone else signs a more lucrative contract.

The easy answer for who is the NFL's highest-paid player is Aaron Rodgers, as his average annual salary of $22 million is tops in the league. That said, he's not the top moneymaker in the league for either the 2014 or 2015 seasons due to his low base salary and lower cap hit. As a result, Jay Cutler and Ndamukong Suh earned the highest base salary and had the highest cap hit, respectively, for the 2014 season, while Drew Brees is expected to earn both distinctions for the 2015 season.