The centre-back, who had made 11 appearances in the 2.Bundesliga prior to his return, was permitted to head back to Merseyside during the winter break in Germany, before rejoining Stuttgart for the second half of the campaign.
That, it transpired, would bring just one appearance for Liverpool’s first team, that being the 1-0 victory over Everton at Anfield.
Phillips also warmed the bench for victories over Sheffield United and Tottenham in the Premier League, but with injury problems easing, he headed back to Baden-Wurttemberg with only 90 minutes to show for it.
It helped Liverpool immensely, though, as Klopp was able to rest Virgil van Dijk after a busy December that saw the Reds forced to field an academy side in the League Cup as the first team were in action at the Club World Cup in Qatar.
From bad to worse
The problems faced in the two years since then make that situation seem amateur in comparison, with the threat of COVID-19 causing a major disruption to the schedule.
While last season saw injuries derail Liverpool’s campaign, this time around the fixture list is under constant revision due to a rise in positive cases throughout the Premier League.
It is no comfort, then, that the Reds are due to play six games in 22 days in January, along with the prospect of the postponed Boxing Day clash with Leeds now taking place during the scheduled winter break at the end of the month.
Those six games are played across three competitions: Chelsea, Brentford and Crystal Palace in the Premier League, Shrewsbury in the FA Cup and a two-legged semi-final against Arsenal in the League Cup.
A busy January
Speaking after the penalty shootout win over Leicester in the quarter-finals, Klopp admitted it “would be helpful” if the semi-final was cut down to one leg rather than two.
With players and staff at risk of testing positive at any time, and restricted squads facing a greater likelihood of injuries due to those absences, the emphasis is on player welfare.
One solution that opens up in January, of course, is the recall of more players from their loan spells.
This is likely an avenue Liverpool are already exploring as a number of their loanees are struggling for game time, and the need to bolster Klopp’s squad – at least temporarily – could amplify this.
Who could return?
Among those lacking minutes at their current clubs are centre-back Rhys Williams and midfielder Leighton Clarkson – both of which featured for Liverpool last term, only to find themselves on the periphery at Swansea and Blackburn respectively this time around.
It would be no surprise if new loans were being lined up for the pair, who have played a combined 624 minutes in the Championship this season, in order to continue their development.
But with no rush to send them back out, it could be that Klopp makes use of the likes of Williams and Clarkson to get through a busy January.
The key date there would be the FA Cup third-round tie at home to Shrewsbury on January 9.
That game is due to take place between the two semi-finals against Arsenal, and with a place in a cup final at stake, it is likely Klopp will prioritise that game.
If personnel is short, then, having Williams and Clarkson available could be a handy alternative against a side that sat 20th in League One heading into Christmas.
Meanwhile Clarkson – part of the youthful side that put Shrewsbury to the sword in a fourth-round replay in 2019 – could lighten the load on a midfield that has suffered with injury, illness and isolation throughout winter.
Neither are likely to carve out long-term roles in the first team in the second half of the season, but the success of Phillips’ brief return in 2020 could be an inspiration for Klopp.
It could prove beneficial for those called back, too, as Phillips himself has demonstrated.
Upon joining Stuttgart in the second tier of German football, the ex-Bolton youngster looked set to fade into obscurity on Merseyside, but that glimpse of potential against Everton convinced Klopp he could take his opportunities.
That trip back from Stuttgart to Liverpool led the 24-year-old to a chance to prove he is capable of being a first-choice centre-back in the Premier League.
So this could well be a win-win scenario for the Reds, allowing Klopp to manage his squad during a precarious time and offer those stagnating on loan a refresh for the second half of the campaign.