He had back, abdominal and thigh injuries, too. He's been bitten by the injury bug quite early.
My impression is that Delpo possessed more power than his body could handle on a regular basis. If he ever lifted weights, he did so ineffectively. Look at Alexander Zverev, this guy deadlifts over 300 pounds, which is not a lot for an elite athlete, but probably quite a bit more than most on the tour. He doesn't seem at risk for injury.
It's a shame Delpo's trajectory took such a downward turn after 2009. He could have done a lot of damage to the Big 4.
My goodness I hadn't fully realized the extent of Juan's injuries nor how early they hit him. He just always looked so big, strong, and healthy. I also had thought he was going to do a lot of damage to the Big 4. No wonder it never happened with all those injuries so early.