Reformed drug addict Murphy has been supporting romantic interest Hayley (Alyssa McClelland) while she attempts to kick her own habit.
However, when he hears that his wife Bianca is in hospital, it may lead him to return to his past drug addictions.
"You don't become friends with a new addict," Whitehead told TV Week.
"It's not good for two addicts, and one who is still partially using, to be together. He's playing with fire, but it's nice to have someone there."
Liam's housemate Leah starts to get worried when she spots him drinking wine in order to relax, and becomes concerned that he may start to take more dangerous substances.
Murphy ended his relationship with wife Bianca after he realised he could not raise her unborn child with Heath Braxton (Dan Ewing).