The 22-year-old winger joined the club on a season-long loan from Belgian outfit Gent in the summer, with an option to make the move permanent.
"Yassine's a young player, coming into a new environment, a different culture, a different way of playing," said Downing to the WBA website.
"He's adapting to the English way. It's not just about attacking but about defensive, positional play. He's just learning his game, going through a period of working on what we're telling him to do.
"He's not just someone we've thrown out of the window. He's still very young, still learning and adapting. In January, when people are away, he will be considered.
"He is learning during this first half of the season, watching and seeing how it should be done.
"It's all a learning curve for him.
"You're asking people to come over from a different culture, different countries and a different way of playing and saying 'right, go out there and play'.
"Some adapt quicker than others."