Wanted Mohamed Elyounoussi is a potential transfer target for La Liga surprise package Real Sociedad - according to a report.
The 25-year-old spent last season on loan at Celtic and impressed despite being limited to only 20 appearances due to injury.
And now Sociedad - who currently occupy fourth place in the Spanish top flight - appear ready to test Southampton's resolve for a player who cost them £16m from Basel in 2018.
Celtic boss Neil Lennon admitted last month he was keen to secure a return for the Norway international who netted seven times in green and white.
But news outlet Todo Fichajes claim Sociedad are ready to strike and reunite the former Molde star with his international teammate Martin Odegaard in San Sebastian.
Celtic remain fixed on Fraser Forster and it's understood a loan deal to bring the England international is becoming increasingly likely.
The Hoops and the Premier League have completed a number of deals together in recent years and Olivier Ntcham is the latest Celtic man who is being watched closely on the south coast.
Southampton are looking to charge on in the market after penning Ralph Hasenhüttl to a new long-term deal that will keep him in place until 2024.
