Slot also needs a striker he can count on, both to score goals and to stay fit, because Diogo Jota and Darwin Nunez are not up to the task, for one reason or another. Had it not been for Salah producing one of the most sensational individual campaigns in Premier League history, Liverpool would not have got anywhere near the title, with the Egyptian breaking the 38-game season record for direct goal involvements.
In that sense, his renewal was absolutely vital to Liverpool's hopes of retaining their title because, even at 32, he is showing very few signs of slowing down. The same pretty much goes for Van Dijk, and it's clear that the prospect of winning even more trophies played a key role in both men deciding to extend their respective stays at Anfield.
Indeed, the captain admitted that he is anticipating "a big summer" of transfer activity, and it would be a major surprise if that does not involve the acquisition of a young striker of world-class potential, which will hopefully be covered - at least partially - by the money raised from belatedly selling Nunez.
Slot, for his part, is giving very little away, saying they're look at players in "every single position", but he is quite open about the fact that there will be a lot more incomings this year.
"Last summer, we didn’t do a lot because we - Richard, me and all the other people involved - just wanted to know how these players would work with me," the manager explained. "Now we have a very good idea about that. I'm not going to tell you which positions we prefer, but it is clear that we've assessed the squad, we've assessed what we think where we can improve, and that's where we try to go for in the summer."
Slot, then, is acutely aware that his second season may be even tougher than this first. There was certainly nothing lucky about their title triumph - it was hard-earned and fully deserved - but they were undoubtedly aided by the fact that their expected title rivals, City and Arsenal, shockingly underestimated the strength of their respective squads. Neither club will not make the same mistake again.
As it transpired, Liverpool were right to stick with what they had, but another window of restraint is simply not an option. Slot may have made putting Liverpool back on their perch look easy - but staying there will be even more difficult.