West Brom chief Garlick welcomes Gomez appointment
Gomez worked with Mel at Real Betis.
Garlick said: "Pepe is working in a completely new environment and we've always been open to the idea of him strengthening his backroom staff with someone he knows well.
"I'd like to officially welcome David to the club. He initially joins us until the end of the season and I'm sure he will provide Pepe with valuable support."