The Reds host Galatasaray in the second leg of their Champions League last-16 showdown on Wednesday night as they try to overturn a 1-0 defeat in the first leg.
Liverpool are fighting for a chance at redemption against PSG, who eliminated them last season.
Anything less than a win at Anfield tonight would set off more boos from supporters who jeered at the side when they drew against Spurs at the weekend.
Now, speaking in the match programme, Slot admits that the clash will not be easy and supporters must get behind the side who may have to go beyond 90 minutes.
"That this is a massive game for us requires no explanation. Having worked so hard to reach this stage of the competition, we want – and need – to continue our journey, particularly after falling short in our attempt to qualify for the quarter-finals last season.
"We know it will not be easy. Galatasaray earned their place in the last 16, and they arrive here with an advantage from the first leg which we will have to overcome.
"Given the scoreline is tight, the possibility exists that we might need to go beyond 90 minutes and, again, this is something that we have to be ready for and even embrace in the event that this situation occurs.
"The onus is on us. This is our opportunity to go to the next round and also to remind ourselves and everyone else what we are capable of. Let's make the most of it."
With Liverpool comfortably out of the Premier League title race, they only have the FA Cup and Champions League to play for. An exit from Europe would mean Slot relies on winning the FA Cup to save his job which is hanging by a thread.