I know the new Babolat balls being used at the French Open are fast, but if Nadal was any deeper behind the baseline he'd be returning serve in Calais:
The 6-foot-9 Isner used his rocket serve to win two of the first three sets during his first-round match with the five-time champion. Nadal has looked uncomfortable all match, like he was unsure whether to stay back and play defensive or take the ball early to create better angles against the lanky American. One serve bounced so high that it almost went over Rafa's head.
The second set of the match was the first one Nadal had ever dropped in the opening two rounds at Roland Garros. Last year, he made it through the entire tournament without losing one. Now that he's down a set, he'll have to go five sets in order to avoid the upset (which he eventually did). Nadal had never played a five-set match at the French Open.