The 50-year-old former Real Betis coach was named as manager of the Premier League club on Thursday but was rebuffed in his wish to bring Roberto Rios and David Gomez with him.
In an interview with Spanish radio station Cadena Ser published in The Sun on Saturday, Mel said he would assess the situation in May.
"You know that my coaching team are two people I love very much and who have helped me a lot in my career," he said.
"At the start, what was clear was that I had to go to Birmingham alone. West Brom wanted me but did not have a place for my assistants.
"The club is structured in a different way. They have a lot of staff and are putting at my disposal people who will help me.
"They wanted a longer contract. We decided to do it until the end of May. I hope that with my work, in May my assistants can be with me because I think it's the most correct way.
"Otherwise it would be impossible."
Mel was watching his new side from the stands on Saturday as West Brom travelled to Southampton with caretaker boss Keith Downing still in charge of the team.
(Reporting by Martyn Herman, editing by Clare Lovell)
