Does a unit heal after taking damage from spells during a showdown on an uncontested battlefield (no combat)?

Ruling: Units do not heal after this showdown because no combat occurred. Units only heal during special cleanup after combat and at end of turn, and combat only starts if attacking and defending units are at the same battlefield.

Sequence:

• Player 1 moves a unit to an uncontested battlefield
• Player 2 casts Hextech Ray to damage/kill it during their focus
• Player 1 casts Discipline in response to save the unit
• No combat occurs (no opposing units present)
• Unit does not heal after the showdown

Nuances:

• Healing only occurs during special cleanup after combat and at end of turn
• Combat requires both attacking and defending units to be at the same battlefield