Roger Federer confused by form after Juan Martin del Potro beats him at US Open

Roger Federer was unable to set up a dream semifinal against Rafael Nadal, wasting chances to take control and missing easy shots in a 7-5, 3-6, 7-6 (8), 6-4 loss to the 2009 champion Juan Martin del Potro in the US Open quarterfinals on Wednesday. “Yeah. Funny, again, I didn't even think about it, as I lost that match, that it's not going to happen. I'm dealing with just trying to understand what happened,” he said. (Video Credit: SNTV)