The striker's last two goals have earned West Brom 1-1 draws at home against Chelsea and Liverpool and Mel believes the 25-year-old will be crucial to the side's survival bid in the Premier League.
Only goal difference is keeping West Brom out of the bottom three.
"Victor is going to be so important to our survival hopes," the Spaniard said. "I've been impressed by him.
"But I was proud of all my players against Chelsea.
"Now they have to show me we have the right mentality to win."
Albion now have nine days without a game and will travel to Spain for warm-weather training. And midfielder James Morrison thinks it will be a good chance to get to know their new coach and his approach.
"It will be good for trying to get used to the gaffer, how we're going to play and what system suits us," the Scotland international told the Birmingham Mail.
"Hopefully it will give us a bit of identity, we can get used to the manager and he can get used to everybody because it's still very rare that we all get together like this."
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