The Queens Park Rangers defender spent the first half of the season on loan with Southampton
Bizarrely, the last time Caulker featured for Ronald Koeman's side was when he endured a torrid evening at the hands of his potential new club in the Capital One Cup. Liverpool decimated the Saints 6-1 to progress to the semi-finals.
Nevertheless, Jurgen Klopp has clearly pinpointed the 24-year-old as the short-term answer to the Reds' problems in defence. The German had none of his established centre-backs available for the FA Cup tie with Exeter last week, and while The Guardian claim that Kolo Toure and Mamadou Sakho should now be available for selection, Dejan Lovren and Martin Skrtel remain on the sidelines.
Having struggled for the south coast club - and having experienced relegations with both Rangers in 2015 and Cardiff City the season before - he will be desperate to prove at Liverpool that he can be the top defender he has often threatened to be.