Sakura and Hakai ran through the forest, trying to keep the sounds of the battle behind them out of their minds in hopes that it wouldn't make them want to turn back and help their friend.
They knew how strong Susa was but they didn't know completely how he compared against a Commander.
They wanted to be optimistic but it was difficult to ignore that he was alone in the fight but they also didn't know what Susa was like in a fight where he had actual opponents and not soft brawls with common strangers or people he wanted to test like he did against Sakura and Hakai.
They didn't forget how difficult of a challenge he had posed to them and that there was probably a good chance that he'd be fine so they wanted to fixate on it.