The 28-year-old moved to St Mary's from Chelsea in February 2015, for a fee believed to be worth in the region of £10 million, having spent the previous six months on loan with the Saints.
He has fully established himself as one of the division's best left-sided defenders during his time on the south coast, and Southampton will be desperate to keep hold of him.
That will be easier said than done, however, with the Daily Mail reporting that Manchester City are closely monitoring Bertrand, with a view to making a January bid for the left-back.
The Citizens are unsurprisingly favourites to sign the England international in January, with BETVICTOR listing them at 3/1 to win the race for his signature.
Somewhat surprisingly, however, BETVICTOR list both Spurs and the Gunners as 8/1 outsiders to obtain the Saints man's signature.
Quite where he would fit in at either club is unclear, with both teams fairly well stocked in the left-back department.
Following Virgil van Dijk's big money move to Liverpool, Saints fans will be dreading the thought of another one of their key men leaving the club, but with the January transfer window just around the corner, that seems like it could be a very real possibility.