I think the plantar fasciitis is way too overlooked by fans in regards to Rondo's past season. He made steady improvement in his first four seasons, and by the end of the 2010 season Rondo was ranked 26th among all NBA players in efficiency. I had high hopes for him going into the 2011 season thinking that as he had improved in each of his previous seasons, there was good reason to expect that he could make the jump to a top 15-20 player.
He got off to a great start. Shaq has to be given alot of the credit for Rondo's amazing start with the assists. Adding him to Pierce, Garnett, and Allen made it like shooting fish in a barrel for Rondo to rack up the assists. Rondo didn't have to work as hard driving the basketball and the offense was the best it's ever looked and one of the best in the league.
Unfortunately, Shaq went down close to halfway through the season, and this would have been the time for Rondo to go back to being more aggressive with the basketball. He couldn't do it, though. The feet must have been killing him by that point. Plantar fasciitis is a condition that really only heals with rest, and he wasn't getting any.
Some other notable players who have suffered from this condition include Kobe Bryant, Tony Parker, and Tyreke Evans. Bryant suffered from it during the '04-'05 season where he only played in 66 games and had one of his poorer statistical seasons and the Lakers actually failed to make the playoffs. Tony Parker was woeful during the 2010 season when he suffered from it, putting up an efficiency ranking of 14.5 in 66 games. He bounced back last year, though, and started playing more like himself. Evans followed his spectacular rookie of the year season by suffering a huge dip in productivity. An overlooked fact is that Tyreke, too, suffered from plantar fasciitis in his sophomore year.
The good news is that players generally bounce back from having plantar fasciitis for a season. It doesn't seem to be a chronic condition, and an off-season of rest and staying off the feet normally cures it.
Keeping my fingers crossed, I expect Rondo to come into next season with two good feet (and a good elbow) and take over where he left off during the 2010 season.