Southampton have reportedly made a bid in the region of £8m for Celtic defender Virgil van Dijk.
The centre-back, who joined the Scottish champions from Dutch side Groningen in 2013, has been linked with moves to Manchester United and Arsenal this summer.
According to The Sun, Saints manager Ronald Koeman believes that the offer is a fair one, with Van Dijk unavailable for European competition after featuring for the Hoops in the Champions League.
Van Dijk, who is a free kick specialist, scored 10 goals in 58 appearances in all competitions for Celtic last season.