According to the Telegraph, the Lazio defender is currently undergoing a medical at St Mary's ahead of his switch to the Premier League outfit.
Hoedt has made 46 appearances for the Serie A side since his move from AZ Alkmaar in 2015 and has represented Holland on four occasions.
The 23-year-old is expected to immediately compete for a first-team spot, but Southampton do not regard his arrival a result of reports linking Van Dijk with a move away from the club.
The Dutchman has been at the centre of intense transfer speculation this summer as Liverpool, Chelsea and Manchester City were reported to be interested.
But the Saints insist the he will not be sold this summer, as chairman Ralph Krueger looks to move away from the perception of being a selling club.
Whilst they remain adamant he will be staying, though, Van Dijk has still not joined up with Mauricio Pellegrino's first-team squad yet this season.
The club are confident the saga will be put to bed and the player will return to training once the transfer window closes.
The news of Hoedt's arrival will be music to the ears of the Premier League's big guns, however, who will feel more confident in prizing Van Dijk away from Southampton now a replacement is in the ready.
