The 20-year-old has forced his way into the first team this season, scoring five Premier League goals in 29 appearances, including a winning effort against West Ham on Saturday.
Berahino has also been at the centre of controversy after failing to hold onto possession in their match with Cardiff City which resulted in West Brom conceding a last minute equaliser.
Mel kept faith with the forward and it paid dividends as Berahino pounced 11 minutes into Saturday's match at The Hawthorns, and the Spaniard believes he will only get better with more games.
"I spoke at great length with Berahino and he knew that he was going to play," Mel said.
"I think that he's a player with an awful lot of talent and a great future ahead of him."
The victory boosted West Brom's survival hopes as they moved five points clear of the relegation zone with three games remaining.
