Virgil van Dijk says he has been left with "no alternative" but to hand in a transfer request in a bid to force a move away from Southampton, as he wants to play European football.
The centre-back, who has been training alone and has not featured during pre-season, said he made the decision to request a transfer after being fined the equivalent of two weeks' wages.
Van Dijk is a long-time target for Liverpool, who apologised to Southampton in June after allegedly being accused of tapping up the defender, an incident the Anfield club described as a "misunderstanding".
In a lengthy statement released on Monday, van Dijk - reportedly valued at £50million - said a move from Southampton would enable him to challenge for honours.
"It is with regret that I can confirm that I have handed in a transfer request to leave Southampton Football Club," van Dijk's statement read.