Does phasing out remove a creature from combat?

When a permanent phases out, it is treated as though it doesn't exist for all game purposes (CR 702.26d). Because the phased-out permanent is effectively nonexistent, it cannot be a legal attacker or blocker, so it is immediately removed from combat (CR 506.4).

CR 506.4 specifies the conditions under which a creature is removed from combat, and one of those conditions is that it phases out. This is an explicit rule — phasing out is listed directly as a removal-from-combat event, not just an indirect consequence of the permanent ceasing to exist.

This matters because normally a creature that leaves the battlefield is also removed from combat (CR 506.4a), but phasing out is distinct — the permanent is not considered to have left the battlefield (CR 702.26d). Despite that, the rules still explicitly remove it from combat, making this a special carve-out.

Example: Your 3/3 creature is attacking and your opponent uses a card with Phasing to phase it out. Even though it didn't 'leave the battlefield,' it is immediately removed from combat — it is no longer an attacking creature, and any creatures that were blocking it are now removed from combat as well (CR 506.4b).

So if your creature phases out while blocking, it is also removed from that blocking assignment, potentially leaving the attacker unblocked for the remainder of combat.