During the fallout of the incident, former Baggies forward Peter Odemwingie suggested on Twitter that Berahino, who later 'favourited' the message, should leave the club in the summer.
When speaking about Berahino in Thursday's press conference, Mel said: "This week he's worked exceptionally well in training and I am very impressed with his positive reaction and what this says for the future.
"In addition to being an excellent player he is also very intelligent. He has shown this in training and I am certain he is going to help us in the next game.
"I've spoken to him throughout the week. He is very positive. He will be extremely important to us in final seven games."
Berahino, whose side are three points above the Premier League relegation zone, is said to have suffered a minor head injury following the incident.