For both the red-carded Hammers midfielder and the Reds substitute now find themselves senselessly suspended for the May 13 showdown following a needless 82nd-minute spat on the halfway line that did little for Anglo-Spanish relations.
By then Djibril Cisse's double had already secured the points for Liverpool in a dress-rehearsal for the Millennium Stadium showpiece that gave few pointers to the likely outcome at Cardiff.
Indeed, from the moment that the team sheets were published, it was clear that there would be few clues to the final showdown as both Alan Pardew and Rafael Benitez kept their FA Cup cards clutched close to their chests.
Indeed, Liverpool made no fewer than eight changes as Steve Finnan, Jamie Carragher and Momo Sissoko were the only survivors from the side that overcame Chelsea in Saturday's semi-final.
West Ham made wholesale switches, too. Jimmy Walker, Lionel Scaloni, Elliott Ward, Bobby Zamora and Teddy Sheringham were all pitched into action as Pardew rested some weary legs following Sunday's victory over Middlesbrough.
Maybe, just maybe, some of the current Hammers side can go on to be trophy-winning Cockney conquerors at Cardiff, but before the game the 34,852 crowd were joined by some 30 victorious East End legends of days gone by, in tribute to John Lyall who died last Tuesday.
But following one minute's hearty applause for the former West Ham manager who served the club as man and boy for 34 loyal years, it was the Liverpool fans that were soon applauding.
In a bid to stake a late claim for an FA Cup final place, Cisse wasted no time sending an awkward low 25-yarder thudding off Walker's ribcage to safety.
And on 19 minutes, the striker and keeper found themselves in combat again after the steam-rollering Sissoko embarked on a mazy run before squaring to Cisse who, this time, drilled another low 20-yard shot between Walker and the base of his right-hand post.
In reply, Yossi Benayoun and Zamora forced the alert Jerzy Dudek into smart low saves, but it was still the Merseysiders who looked the more dangerous as Cisse headed a whisker wide, Robbie Fowler floated his cheeky chip inches over and the impressive Sissoko tried his luck from long-range.
Certainly, Fernando Morientes looked to have put yet more daylight between Liverpool and Pardew's men but his effort was ruled out for offside, while at the other end, both Sheringham and Benayoun each went within inches of heading home an unlikely equaliser as the first half drew to a close.
Within just a minute of the restart, however, West Ham were level after Zamora played an intricate one-two with Sheringham before unselfishly inviting his unmarked skipper, Nigel Reo-Coker, to roll home his fourth goal of the season.
But the Hammers joy was not destined to last long. After Morientes hit the bar, Fowler then sent Cisse racing clear on 54 minutes and, again, the Frenchman got the better of the advancing Walker as he squeezed a low 15-yarder through the luckless keeper's legs to claim his 17th goal of the campaign.
Although the acrobatic Dudek was twice forced to claw out Matthew Etherington scorchers, the fearsome force of Sissoko allied to the precocious pace of Cisse had West Ham constantly on the back foot.
Indeed, Cisse - searching out a hat-trick - sent another angled shot ripping into the side-netting before crossing to an unmarked Fowler who sent his free header wide, only to be immediately replaced by Garcia.
But, within seconds, that late switch was destined to have a devastating effect on both Mullins and the Spanish substitute, who gave referee Howard Webb no option but to dismiss them when they tangled on the halfway line in a costly climax to the evening.