Fighting without paying attentions to your surroundings is not a smart idea for a hero, as Todoroki and Bakugo learn when Aizawa interrupts their fight. Getting on the bad side of the grumpy and perpetually sleep-deprived teacher is not a good idea.
The internal struggle revolving around his powers is something that Todoroki has dealt with for a long time. Midoriya tried to help him but it seems that he also needed some help of a different variety. And this time Aizawa decided that someone else needed to take the initiative.