Martin Jol too elected for changes, just not so many. The fit again Anthony Gardner was restored to central defence in place of Noureddine Naybet, while there were also starting spots for Michael Brown and Fredi Kanoute - replacing the benched Pedro Mendes and Jermain Defoe.
In a funny sort of way, Liverpool were in a no-lose position whichever the outcome favoured. Had they won they could have congratulated themselves over the depth and talent of their squad, whereas a loss can simply be put down to not having the regulars on the pitch.
Kanoute set an early tone on five minutes when he brilliantly chested down Reto Ziegler chip into the area, the striker spinning on the spot and lashing a shot that crashed against the bar.
First or second string, it was not going to be easy to establish an upper hand in the central areas of the pitch, with the towering Igor Biscan and Salif Diao stalking the centre circle - messrs Carrick and Brown had a big job on force authority against these two internationals.
It was following great work from Keane that Jerzy Dudek had to race from his line to smother at the feet of Ziegler. On 14 minutes the Swiss rasped an effort into Dudek's right side netting. A whipped and measured cross by Kanoute on 19 minutes provided an open invitation for Ricketts to nod us into the lead, but the midfielder went for a glanced header that drifted harmlessly wide.
A the midway point of the half, domination was there and only a goal was missing. The boys were snapping into their tackles and Liverpool were given no time to settle. The influence of the aforementioned visiting midfielders was minimal and goal seemed to be a when rather than an if.
Keane so nearly realised that when when he employed a range of tricks in the area following a corner routine on 36 minutes - he shot powerfully but the advancing Dudek saved bravely.
Liverpool started the second period brightly before, on 52 minutes and with future assignments in mind, took striker Neil Mellor and replaced him with middleman John Welsh.
It was Keane though who should have opened the scoring a minute later when a fumble by Dudek allowed him a strike on goal, but his powerful effort hit the outside of the net.
Just before the hour there was a miraculous save by Dudek. A surging run and pass from Ziegler found Kanoute who strode down the right to the touchline and crossed for Keane to volley goalwards, the ball hit the ground and appeared to be going in before the Pole managed to parry over the bar.
It was come in No.18 on 65 minutes with arrival of Jermain Defoe for Ricketts -certainly by popular demand of the 36,100 crowd.
There was a big let off in the 77th minute when Gardner slipped in a duel with Sinama Pongolle and hauled the jet-heeled frontman down when seemingly clear on goal. Thankfully, referee Mr Barry elected to wave only yellow.
It was Liverpool who entered the final phase on top and threatening a late strike. It was the youngsters Pongolle, Potter, Welsh and sub Smyth coming to the fore and Martin Jol reacted by bringing on Pedro Mendes in place of Keane.
Given the way the game was shaping up, extra time was not an entirely enthalling prospect and it was clear great improvements were needed against the energetic visitors.
But extra-time it was for the second time in our Carling Cup trail - Bolton was enjoyable, how would this pan out?
Welsh came within a fraction of scoring five minutes into the 30 when he cut in from the left and dispatched a curling shot that left Robinson flailing before Pongolle should have done better from a run on goal.
Defoe worked a passage to goal on nine minutes - beating three players on the way - before, with boot ready to rocket, Raven came across and lunged in bravely with a last ditch challenge to save his team.
Defoe again tried his luck with a drive from outside the area a minute into the second period of extra-time but Dudek was equal to it before, one minute later, the same player netted a most welcome goal.
It was almost a carbon copy of Sunday's opener against Middlesbrough, only this time it was Kanoute's supply from the right, rather than Mendes. The finish was the same - emphatic.
Five minutes from time a corner connected with Kanoute's hand, giving Liverpool the chance to level from the spot which Pongolle gratefully accepted. The team perhaps made the mistake of retreating in order to see out the game and were punished. They then went for the jugular again in the final minutes before time ran out and penalties loomed for the second time in two seasons at the last eight stage.
Liverpool went the for the full monty as far as team selection was concerned - or rather a full reserve side. Were every Liverpool squad member fit and given this season's starting X1s, it is possible that not one the line-up here would be a regular Saturday starter.