When looking for an MMA fighter who had his potential severally blunted due to injury look no further than Mauricio Rua. The Brazilian exploded on to the MMA scene in 2003 when he appeared in Pride in his early 20's. Rua's blend of explosive athleticism and dynamic skills lead him to win his first eight fights in the promotion. That included running through the 2005 Grand Prix, one of the most formidable fields of Light Heavyweights ever assembled.
Rua was seen much in the same light as Jon Jones is currently in terms of his athletic ability and accomplishment. When Pride was finally purchased by Zuffa, Rua was 16-2 and was widely considered to be one of the best fighters in the sport.
Then in the lead up to his UFC debut against Forrest Griffin Rua injured his knee. Rua fought regardless and then lost not only the fight but also the entirety of 2008 to knee surgeries and recovery. Since then, while Rua has come close to regaining his previous form, he never quite was able to replicate his 2005 success, going 5-4 in his career since his knee injuries.
The comparison to Jose Aldo can be made, he is a fantastic fighter who relies on his athleticism to make the most of his exciting and dynamic skills. He is currently the same age Rua was during his run through Pride and Aldo is already beginning to pile up the injuries. The neck injury that delayed Aldo's UFC debut clearly affected his performance against Mark Hominick at UFC 129, as Aldo clearly tired late and allowed Hominick to come back into the fight.
Aldo has never lost his winning ways though, remaining of a 14 fight win streak, and he did convincingly defend his title against Kenny Florian and Chad Mendes. But then an undisclosed injury forced back Aldo's match with Erik Koch, and then a foot injury sustained in a motorcycle injury cancelled the match all together.
Aldo lost basically all of 2012 because of injury and now he returns to an extremely tough test in Frankie Edgar, whose famed durability will likely cause this fight to be dragged into deep waters. It is entirely possible that Aldo overcomes these injuries in the way that some truly special athletes do, like Adrian Peterson returning from his knee injury. But neck and lower body injuries extract a long term price on the body, and whatever consequences of that price very well could be laid bare for all to see in the later rounds against a relentless fighter like Edgar.
A loss to Edgar would hardly end Aldo's career, he would remain an elite Featherweight, much as Rua was able to win a UFC title and is still a top flight Light Heavyweight. But time will tell if these injuries are going to have a lasting effect on a man who was once considered one of the brightest prospects MMA had to offer.