Southampton's Virgil van Dijk is the defender who Liverpool have identified as the first-choice summer signing to strengthen their leaky defence, according to widespread reports.
The Netherlands international is thought to be rated at around £50 million by the Saints and the Reds are willing to go head-to-head with a number of clubs for his signature.
Van Dijk is attracting interest from Premier League rivals including champions-elect Chelsea, Manchester City and Everton, while even Real Madrid are thought to be monitoring his situation.
Southampton are under no pressure to sell Van Dijk, who signed a new six-year contract on the South Coast just last May, but it is thought they are increasingly resigned to losing their prized asset.
The 25-year-old hasn't featured since January due to ankle ligament damage but is one of the most sought-after players in the upcoming summer transfer window.
Liverpool join race for in-demand defender
Southampton's interest in Liverpool outcast Mamadou Sakho - currently impressing on loan at Crystal Palace - could aid their cause as they compete with a number of other clubs.
With no clause in Palace's loan deal to sign Sakho for a set fee in the summer, Liverpool are free to push for as high a fee as they desire - with £30 million the reputed fee they are looking for for the Frenchman.
Former Celtic defender Van Dijk has been in excellent form both this season and last, cementing himself as an invaluable member of Southampton's back-line within months of his switch to St Mary's back in September 2015.
Van Dijk was crowned Player of the Season last year, his first campaign with the club, and was named captain after fellow defender Jose Fonté left for West Ham United last summer.
Southampton conceded only 36 goals in 34 top-flight games that 6ft 4ins Van Dijk appeared in last term, while before his injury Claude Puel's charges had only leaked 23 goals in his 21 league appearances this season.
Liverpool's defence is in desperate need of similar stability. Niggling injuries to Dejan Lovren and Joël Matip throughout the campaign have prevented Klopp from selecting a consistent partnership at the back.
Liverpool have conceded 40 goals in 32 Premier League games this season after letting in 50 in 38 under Klopp the year before, with Matip's arrival on a free transfer from Schalke unable to settle an unreliable back-four.
Reds hope Van Dijk can end defensive woes
Van Dijk is thought to be the player Liverpool believe will solve their defensive issues as they look to strengthen for a 2017-18 season in which they hope to add Champions League football to their schedule.
Liverpool currently sit third, two points ahead of fourth-placed Man City who have a game in hand, with six games to go and face West Bromwich Albion at the Hawthorns this season as they look to move one step closer to sealing a return to Europe's top-tier competition.
It is thought the Merseyside outfit are willing to spend more money than ever in the transfer market in a few months' time in order to build on the progress made under Klopp in 2016-17.
Liverpool had been touted as title challengers before the festive fixture schedule, when injuries hampered Klopp's options and highlighted the Reds' lack of quality squad depth.
The most the club have ever spent in a single window stands at £117 million from the 2014-15 season, though £75 million of the pot that summer was funded by Luis Suárez's sale to Barcelona.
Among the other names linked is energetic RB Leipzig midfielder Naby Keïta, with Klopp thought to be a huge admirer of the 22-year-old - who has scored seven goals and laid on eight assists in 25 Bundesliga appearances this term.