The Reds are keen to wrap up a deal as soon as possible and have told the Saints that they will not make a bigger offer, while team-mate Lambert should complete his move shortly
Liverpool have made a final £25 million bid for Southampton forward Adam Lallana.
The Reds are keen to tie up a deal as soon as possible and are adamant that they will not return with more money should the Saints knock back their latest approach.
Tottenham are also in the race to sign Lallana but it is the Merseysiders who have shown concrete interest with two formal bids.
The first, worth around £20m, was made on the final weekend of the Premier League season but was rejected by the Saints.
The south-coast club are holding out for nearer to £30m for the England man, but Liverpool will test that resolve by making it clear that they will not stretch any further than £25m.
Lallana's club and international team-mate, Rickie Lambert, will complete his Anfield move over the weekend after completing a medical on Saturday.
Both players will travel to Miami with the England squad on Sunday as they step up preparations for the World Cup in Brazil.
The Three Lions beat Peru 3-0 at Wembley on Friday evening thanks to goals from Daniel Sturridge, Gary Cahill and Phil Jagielka.
Roy Hodgson's men will play Ecuador on Wednesday and Honduras next Saturday, before opening their World Cup campaign against Italy in Manaus on June 14.