What is the advice for someone who is confused between specializing in mathematics and physics or studying Islamic sciences at university, while desiring to delve deeply into Islamic sciences?

Your brother can continue his studies in sports specialization alongside studying Islamic sciences under the guidance of a scholar, or later join Islamic institutions. However, if he fears that sports sciences will distract him from Islamic sciences, then he should abandon them and devote himself to seeking Islamic knowledge, as it is more beneficial and important, and through it, Allah is worshipped with clear understanding.