San Diego Chargers quarterback Philip Rivers is set to enter his 15th season in the league, which has pressed forward the question of much longer he plans to continue playing.

Rivers has been firm in his desire to play a few more seasons that should have him on pace to be still under center into his 40s. However, he has had much difficulty at this point pinning down how much longer he wants to play in the NFL, according to Albert Breer of SI.com.

Much of this unwavering desire to continue playing may lie on the fact that he's still playing at a high level after coming off yet another highly productive campaign. He finished fifth with 28 touchdown passes, second with 4,515 passing yards and ninth with a 96.0 passer rating. This marked the fifth straight year with more than 4,000 passing yards and 25 touchdowns.

He had also picked up his performance in the second half of the season where he threw 11 touchdowns with just three interceptions in the last seven games that saw him lead the team to six wins over that span. The 36-year-old has shown no drop off in his performance on the field with the extra motivation of pursuing the first Super Bowl appearance of his career while the Chargers haven't reached the playoffs in five years. Keep in mind; he still has two more years left in his four-year, $83.2 million deal.

Ultimately, this may all depend on how his body holds up over the next couple of years as he still has a strong passion for the game.