Clerics are more than just healers and medics in . While being the original class with the Cure Light Wounds spell, they have evolved into much more through each sourcebook and full edition of the game. They are competent with many useful weapons, armor, and shields.
Both the main Cleric spell list and several Domains specialize in damage output and subduing the enemy. In the right hands, a Cleric is more of a divine Wizard than a protector.
It especially helps if the actual Cleric player is motivated to go head-on into battle. As the DM, encourage them to make several narrative decisions during session zero.
This will allow their character to shine and allow for more personal connection during the whole campaign. A player who feels like a healing accessory might lose motivation in both the story and the group entirely.
Also, show the rest of the team the importance of a short rest and using potions wisely. Among the first aspects of a strong melee or caster Cleric is establishing their religion and/or Domain.