The 29-year-old forward joined Southampton last summer from Genk and failed to find the back of the net in his eleven league appearances.
Onuachu has yet to feature in the league for Southampton this season and he is not in Russell Martin’s plans.
Southampton are looking to offload him from their wage bill and his former club, Genk, are interested in taking him back.
The Saints were exploring a deal to offer Onuachu to Genk in exchange for Joseph Paintsil.
But Paintsil refused to move to the Championship despite Genk’s attempts to convince him.
However, Onuachu’s move to his former club is still on the cards, as the player is still keen on joining Genk, according to Belgian journalist Sacha Tavolieri.
The switch for the tall striker could happen in the final days of the transfer window.
Onuachu was a prolific goalscorer during his time at Genk and the Belgian side believe he could slip back into his groove in familiar surroundings.
