McAllister began his rugby league career with Portadown RFC as a way of keeping fit during the union off-season, but received a call-up to the domestic Ireland squad for its internationals in 2015.
He could now embark on a professional career in England, but it is still not certain for which club he will play.
“I’m planning on going over to England for the next rugby league season, but I don’t know which club I’ll be going to yet,” McAllister told local Ulster paper The Leader.
“I’ve been talking to a few teams at League One level (the third tier of English rugby league) but I have to speak to people this weekend and take things from there.
“The first league game is around the end of February but I think it’s quite a long pre-season so I’ll have to go over before then.”