This is coming just months after he joined the west London side.
The 20-year-old was brought in from Norwegian club Molde in January, and he went on to feature in just three Premier League games.
However, reports emanating from west London said that the young striker could now be set for a loan switch in his bid to play regular first-team football.
Sky Germany reports that Bundesliga outfit Union Berlin are desperate to secure his services.
Bild also claimed that a deal could be finalised in the next few days.
