When Lisa was in front of the mirror, brushing, after she knew that she wasn't a part of the lineup of the players for the 2011 Team USA, there were no post-it written in a white index card saying "Where there is no struggle, there is no strength" but on the next scene, there is that white index card.
When Lisa was staying in George's apartment, after being so angry with Matty (due to what he said) that made her packed her things & left Matty's apartment, and waiting for George to make his own drink, she was drinking Guiness. When the scene showed the glass of Guiness on the box, she seemed to have taken it with her right hand. But right in the next scene, she took it with her left hand.
When Lisa is speaking to Matty on her phone while taking up a garbage bag, she knocks over the bin and it falls on its flat side, remaining stationary. The scene cuts to Matty who speaks for only a second before cutting back to Lisa. This time the bin is on its round side and is rolling back and forth, though Lisa doesn't seem to have moved and had practically no time to flip the trash bin.
The scene from the "Nationals'" bullpen where one of the Nats relief pitchers throws a note to a female fan in the stands was actually filmed in the visitors' bullpen at Nationals Park. The visitors' bullpen (in left-center field) is more open and sunny (scene was filmed in the morning) while the real Nationals bullpen (in right field) is shaded by the stands above it.
After their first night together, Lisa is seen wearing a red camisole that has straps showing after putting on her red dress from the night before. The straps didn't show during their date and after she got home.
When he is typing an 'email' to his dad explaining why he needs to think about what he has just heard, he is actually using Word 2010, and although has typed about 20 words, the word count is stuck at 0 (bottom left)