If It's worrying you enough to ask that here, it is definitely worth bringing up.

Before bringing anything up have a think about exactly what it is that is worrying you. Is it just that specific question of "how is your day" or are you feeling that he is not showing interest in what you are doing in your life in general? Also think a bit about how your communication is going in general and whether the issue is about him not asking, or maybe a mismatch in communication style - for example if you tend to lead with a lot of questions straight away but he tends to have more space in a conversation before he initiates things, then the answer would be not just for him to ask more, but for you to also allow a bit more space for him to do so.

With a clearer idea of what the issue is it makes it easier to raise it in a problem-solving rather than accusatory manner. So using my previous example, instead of saying "why don't you ever ask how my day is going" you can ask something like "I feel like I ask about your day more than you ask me. Do I need to give you more space to ask things, or is there something else?". That is much less likely to get a defensive reaction, and more likely to lead to a productive discussion that can help improve things.