Southampton are targeting the signings of Swansea midfielder Gylfi Sigurdsson and Leeds defender Pontus Jansson this summer, Sky sources understand.
Both players are under contract at their respective clubs until June 2020 but Southampton believe they can lure them to St Mary's if the pair are faced with the prospect of playing in the Sky Bet Championship next season.
Sigurdsson, 27, is fighting a relegation battle with Swansea, while Sweden international Jansson expects to secure a play-off place with Leeds.
Southampton have been tracking Sigurdsson, whose family are settled in Swansea, for two years and made an attempt to sign him last year.
Sigurdsson has been vital for the Swans this season, having scored nine goals in 35 appearances for the Welsh club in the current campaign.
Centre-back Jansson has been a key part of Leeds' promotion bid, initially joining the club on loan, while Southampton have been left without key defender Virgil van Dijk since January after he suffered an ankle injury.