This "Who Powered Through" is more about the tough circumstances El Capitan had to deal with this season rather than him overcoming some sort of injury/health related issue for a game or week. Although this season could be described as a "down year" for Philip Rivers, it's one of his most impressive when you consider some of the following factors:
Philip was the 3rd most sacked QB in the league this season. Seriously. That's not including all of the times he was hit while throwing the ball either. The only two players that accounted for more sacks this season were Jay Cutler and Joe Flacco. That means that the offensive line didn't have it's best year in protecting the team's best player.
However, with that being said, Philip still managed to finish amongst the top in the league in terms of completion percentage (3rd), attempts per game (11th), passing yards (1st), TDs (5th), and QB rating (2nd). Well, so was Tom Brady...right? Sure, but Brady's line did a better job of protecting him and he plays in an offense that focuses on short routes that get the ball out quickly. By comparison, Rivers' was the best in the league in yards per pass attempt (1st), % of throws for 1st down (1st), passes for 20+ yards (1st) and passes for 40+ yards (1st).
In a nutshell, even while getting sacked more than most QB in the league, Rivers continued to throw the ball downfield more than any other QB and somehow managed to be efficient while doing so. That's an incredible feat, made even more incredible when you consider point #2.
Here is a list of the leading receiver (by # of receptions) for each of Rivers' 16 games this season:
Legedu Naanee/Antonio Gates
Buster Davies/Antonio Gates
Jacob Hester/Darren Sproles/Antonio Gates
Mike Tolbert/Antonio Gates
Vincent Jackson/Randy McMichael/Darren Sproles
There are 11 names on that list. In 16 games, Philip Rivers had 11 different top receivers. Looking at this list, you'd think that two most important people for Rivers to have would be Sproles (not a starter) and Gates (played about half of the season). Most of the league's best QBs are up there because they had great health around them, and were throwing to the same guys all season. Rivers spent most of his year just trying to learn the names of his WRs before drilling them in the chest with footballs.
3. Running Game
Was it an improved running game? Absolutely. It pretty much had to be, after being worst in the league in 2009. At one point the Chargers even had the #1 rushing game in the league! However, the fact that they finished with the 15th best in terms of yards and 19th best in terms of yards per carry should tell you that it did not stay strong all season.
Many games were played in the same fashion as 2009, with Norv Turner and the offensive coaching staff yelling "Save us, Philip!" into the headset instead of actually calling plays. With the fate of the team resting on his shoulders, Rivers was imperfect....but still great. The times he had a strong running game behind him, he nearly was perfect. If the running game can continue to improve, it is only going to make Phil's life easier.
4. Playing from Behind
I'm not going to go back and see how much football Rivers played from behind because it's depressing. Let's go with "a lot", and it was almost all the fault of fumbles by other offensive players and a Special Teams unit that could've sunk the '85 Bears.
It's wonderful that Philip has such great confidence in his receivers, especially when he has Gates, Jackson, Floyd and Naanee out there. However, when playing from behind he can't be quite as reckless as he usually is. This is why Sproles finished the season with more catches than any other Chargers player. Then, once it gets to the point of "nothing left to lose", Rivers almost has to become too reckless and ends up forcing passes that turn into turnovers to end football games.
For much of his career, Rivers has played in games where his team is either leading or at least within range to make a comeback. For far too much of this season, he played behind by more than one score and without much help around him. This is part of the reason Carson Palmer fell apart this season, and many NFL QBs do in that situation. Rivers somehow managed to keep himself in the MVP discussion.