Cody Gakpo had been strongly linked with a move to their old rivals down the East Lancs Road, but instead of Manchester United, the 23-year-old Dutchman will be playing his football at Anfield after sealing a move to Merseyside worth a reported initial £37million (€42m).
One of the other reasons it came as a surprise was all the talk around Liverpool's transfer activity being based on the midfield, an area where Jurgen Klopp has struggled for consistency both in terms of performances and availability.
However, with attacking pair Diogo Jota and Luis Diaz both out of action for the next two or three months at least, Klopp has focused on adding to his forward ranks instead, and on paper Gakpo is an interesting choice.
So, why have Liverpool turned to him in their bid to kick-start a disappointing campaign?
Dominating the Eredivisie
Gakpo settled well in the Dutch top-flight after coming through the ranks at PSV.
After making his debut as an 18-year-old in February 2018 against Feyenoord, he improved for goals year-on-year, eventually making 159 appearances, scoring 55 times and recording 50 assists for the club.
But it's since the start of the 2021-22 season that Gakpo has found another level, with no player having more goal involvements in the Eredivisie in that time than his 46 (21 goals, 25 assists). In fact, no other player in Europe's top 10 leagues has tallied both 20+ goals and 20+ assists over the same period.
Only Ajax's Dusan Tadic (44 involvements) comes close among Eredivisie players, having played seven more games than Gakpo (48 to 41).
His form earned him a spot in Louis van Gaal's Netherlands squad for Qatar 2022, where Gakpo became the first Dutch player to score in his first three World Cup games.
He did so from a centre-forward position, but Gakpo has primarily featured from the left of the attack for PSV, and that could be where he gets most of his minutes at Liverpool.
How he compares to Liverpool's attacking options
Despite playing as something resembling more of a classic number nine for the Oranje in Qatar, Gakpo was deployed from the left in the majority of his appearances for PSV this season.
But the fact he's been able to operate in different roles for PSV and the Netherlands will have been another tick for Klopp, who could opt to use Gakpo centrally if needed once Diaz and Jota return.
In the meantime, expect to see him on the left, with Mohamed Salah on the right and Darwin Nunez down the middle.
Both will look forward to playing with someone who can provide ammunition from a wide role, with all 14 of Gakpo's assists in games he has started this season for PSV coming from him playing on the left.
But beyond his output, Gakpo looks a good stylistic fit for the Reds. Quick, dynamic and good on the ball, he possesses the ability to both beat his marker and stretch play.
Salah is, of course, Liverpool's key man in attack, but Gakpo's arrival should relieve some of the burden on the Egyptian.
Of Liverpool's forwards, only Salah has been more creative than Gakpo this term, creating 2.2 chances from open play per 90 minutes in the Premier League, while the Dutchman has managed 2.0 per 90 in the Eredivisie.
Gakpo actually averaged more shots per 90 than Salah (4.1 to 3.6), though that's perhaps to be expected given he was PSV's talisman, and the comparative strength of the Eredivisie in relation to the Premier League should also be taken into account.
Nevertheless, it highlights Gakpo's positive mentality and the sort of attacking intent he should bring to a frontline that has been erratic this season.
Having the right mentality can be a vital element when it comes to thriving under Klopp at Liverpool considering the intensity they play at when at 100 per cent. That goes beyond chance creation and shot frequency, though.
Perhaps one of the main attributes that attracted Liverpool to Gakpo is this regard is his ability to win the ball high up the pitch, a key part of their high pressing approach.
Gakpo has won the ball in the attacking third 0.8 times per 90 this season in the league, more than any of Diaz (0.6), Salah, Roberto Firmino (both 0.5), Nunez (0.4) or Jota (0.0).
Can Gakpo fill old shoes?
One player who particularly excelled in such an intense role for Liverpool was Sadio Mane, who left the club for Bayern Munich at the end of last season.
Many have argued that one of the key reasons for the Reds' inconsistent form this campaign is the absence of Mane, with Diaz and Nunez both considerably different players to the Senegal star.
Gakpo could hardly be considered a Doppelganger either, though aspects of his style can be compared to Mane, who won the ball back in the attacking third 0.7 times per 90 in the Premier League last season.
The Dutchman's numbers this year are almost all ahead of Mane's from last year, though again the strength of both leagues must be taken into account.
Mane averaged 2.7 dribbles per 90 with a 54.7 per cent success rate. His frequency of 0.3 big chances created per 90 was way down on Gakpo's 1.0 average this term, while the former Red tallied 3.1 shots each game.
He scored 16 goals in 34 league games last season before departing Anfield, but provided just two assists, so in Gakpo Liverpool arguably have someone more adept at being able to both score and provide.
The pressure will be on Gakpo straight away as there is a gaping hole on the left of Klopp's attack until Diaz and Jota return, but if his career trajectory and numbers are anything to go by, it's reasonable to think he can have a similar impact to the one Diaz had when the Colombian arrived from Porto last January.
It is, at the very least, a statement of intent as Liverpool look to recover their season.
