Now that Virgil van Dijk has officially joined Liverpool, one of the big questions is what number will he wear.
The Dutch defender joined the Reds from Southampton on Wednesday for a world-record £75 million fee in a move that will become official on January 1 when the transfer window re-opens.
It is expected it won't be long before Jurgen Klopp's big transfer target finds his way in the heart of the Liverpool defence.
And when he does, Van Dijk will be sporting the No.4, noted in the Liverpool statement announcing his signing.
Alberto Aquilani, Jason McAteer, Kolo Touré, Nuri Sahin, Raul Meireles, Rigobert Song, Sami Hyypia, Steve Nicol, Virgil van Dijk #LiverpoolsNumberFour — Andrew Beasley (@BassTunedToRed) December 27, 2017
The number has had a mixed run in Liverpool history. Steve Nicol wore it during his 13-year tenure with the club in the 1980's and early 90's, albeit in the pre-Premier League age when players did not use assigned squad numbers. Sami Hyypia then took the No. 4 during his 10-year run with the Reds, which saw a Champions League title. Fan-favorite Kolo Toure sported it in his three-year spell.
However fans will be hoping it goes a lot better for Van Dijk than it did for another high-profile signing from a decade ago. Alberto Aquilani, who wore the number during part of his time at the club, came in with high hopes and expectations, but never fufilled them at Anfield as injuries derailed his promising career.
But the expectations Aquilani faced will be nothing the big centre-back has on him when he lines up in the defence, as he tries to bring order to a unit that has been highlighted as a weak point in Liverpool's high-flying squad.