Saints signed Onuachu from Genk, where he enjoyed a prolific spell, and the Belgians want him back this summer.
A possible swap deal with Joseph Paintsil going to Southampton did not happen, but Genk are still trying to sign Onuachu.
It had seemed they had a good chance of doing so but, according to Belgian journalist Sacha Tavolieri, Southampton have increased their demands for the striker.
They now want more money for Onuachu.
And that has made Genk’s job of signing him much tougher.
It is unclear if they will now be able to reach an agreement with Southampton and snap Onuachu up.
Onuachu may face a season of limited game time if he remains on the south coast, especially as Southampton are signing Ross Stewart from Sunderland.
