The Saints are looking to strengthen their Champions League bid by bringing in quality in the winter transfer window and they feel that Mokotjo would enhance their squad considerably.
The 23-year-old, who has been a mainstay in FC Twente's team this season, is reportedly available for around £6 million and Southampton could try and rush through a deal before the deadline.
Impact for Southampton?
Mokotjo's arrival at St. Mary's would provide them with some much needed squad depth, as they enter the closing stages of the campaign.
Although Southampton's first-team is among the best in the Premier League, they do not have the same level of cover as many of their top-four rivals and this would help them compete in that sense.
Southampton have strong links in Holland after Ronald Koeman's appointment and they have already had success in the Eredivisie market.
Koeman will know exactly what he is getting with Mokotjo, too, as he has previously worked with the central-midfielder when they were both at Feyenoord earlier in their careers.