Naruto Shippūden: Season 2, Episode 45

2 - 45: The Consequences of Betrayal

Kabuto creates a fake corpse that resembles Sai, containing hidden traps to slow down Yamato's clone after sensing it. Naruto hasn't completely recovered from using the Demon Fox's chakra, and Yamato says that he will be left behind if he cannot keep up. Naruto is determined to finish his mission and not slow the team down. However Team Kakashi is forced to take a break when it's clear that Sakura has not fully recovered from her own injuries. Yamato then uses this opportunity to talk to Naruto alone and reveals to him that the one who hurt Sakura was Naruto himself. Naruto is shocked by what Yamato says to him.