Liverpool's summer recruitment drive is likely to centre on the restructuring of their defence, having added impressively and consistently to their attacking qualities since manager Brendan Rodgers arrived close to two years ago.
It is possible that Rodgers will look to bring in a number of players to feature across the back line over the summer, though the right-sided centre-back position appears to be the role that needs attention both for the coming season and those beyond, in finding the ideal partner for Mamadou Sakho over the longer term.
Caulker joined Cardiff last summer for around £8 million after finding his first-team chances at Spurs limited. He has been a regular for the Welsh side this season, playing all 27 matches so far, but with his team struggling near the foot of the table, there is a good chance this could be their only season back in the top flight.
Should Cardiff go down, as an England international hopeful and a player who has proved his ability at the highest level, the 22-year-old is not likely to want to spend time in the Championship.
English players, of course, command a higher transfer fee in the market—whether this is because of paucity of options or over-stated ability is up for debate—but the truth is, he's pretty much the best of the available targets if any clubs are looking to sign home-grown players.
He might cost the same or more as Cardiff invested in him a year ago, but Caulker arguably has the potential to prove more than worth the price.
So how does he compare this season to other centre-backs, statistically speaking?
To compare Caulker's talents viably, a range of key defensive metrics can be measured against other centre-backs from the Premier League: Liverpool's two options in Martin Skrtel and Kolo Toure, an English defender in Gary Cahill playing for honours at the top of the Premier League and a lower-end of the table defender who is regularly lauded as "good enough" for better clubs, Ryan Shawcross.
WhoScored.com (@WhoScored) February 27, 2014
Pass completion statistics show an obvious trend: Those at the better clubs have a higher completion rate, doubtless as a result of making more recycling passes with their teams having more of the ball. Caulker and Shawcross complete 74 and 75 percent respectively, Toure 86, Cahill 87 and Skrtel 91 percent.
Tackles and clearances are measured on a per-90-minutes basis to normalise across different numbers of appearances, while aerial duels won are as a percentage.
The figures show that although Caulker does not reign supreme in any one area, he does score well throughout the preferred areas rather than being reliant on one area of his game.
One potential area of concern may be his headed duels win percentage; though he would fit in well at Anfield if he maintained his close-to-4.00 headers won per game, his actual win percentage is only 60 percent, lower than Skrtel's 67 percent and perhaps a good 10 percent lower than Liverpool need a new, dominant centre-back to be.
The only Premier League defender to win more aerial duels than Steven Caulker this season (104) is Hull's Curtis Davies (106).— Squawka Football (@Squawka) February 27, 2014
However, Caulker has been extremely reliable in his all-round game for Cardiff and can count pace and upper-body strengths as facets of his game, both of which would benefit Liverpool's defence as a whole.
One final impressive statistic that favours Caulker: He has not made a single defensive error in league play this season.
Of the others, only title-chasing Cahill can match that. Liverpool's pairing of Skrtel and Toure have made three each, while Shawcross has made an eye-watering five—leading to two goals against Stoke.
Do Liverpool go English?
It shouldn't matter, but it ultimately does; European squad quotas and the Premier League demand that clubs register a number of home-grown players. The likes of Andre Wisdom and Martin Kelly may boost Liverpool's tally next season, though it is possible that a departure for Glen Johnson could reduce it.
Should Liverpool sign Steven Caulker?
This will be far from the primary concern of Rodgers and the transfer committee, but if they think Caulker can partner Sakho for half a dozen or more years, it's a good bonus to have in place.
The final months of this season might tell watchers an awful lot more about Caulker's mentality, reliability under pressure and ability to stand firm against ceaseless attacks when it matters most, as he tries to help Cardiff beat the drop over the final 10 or 11 games.
If he doesn't achieve that, it could be open season on Cardiff's best players, of whom Caulker is certainly one.