Radamel Falcao and Adrian had big shoes to fill when they arrived at Atletico Madrid last year but they have both scored goals that have given the Spaniards a chance to repeat their 2010 Europa League triumph.
Atletico supporters were worried when 2010 World Cup Golden Ball winner Diego Forlan left for Inter Milan and big-spending Manchester City snapped up Argentine Sergio Aguero but the performance of their replacements in Europe have gone some way to appease them.
Colombia striker Falcao has netted 10 times in the latest edition of Europe's second-tier club competition, level at the top of the scoring chart with Schalke 04's Klaas-Jan Huntelaar, although he is still some way short of the record of 17 he set last season during Porto's title-winning campaign.
Known as 'the tiger', Falcao struck twice in last week's 4-2 semi-final first leg success at home to La Liga rivals Valencia and his total of 27 goals has lifted him to third on the all-time list of UEFA Cup/Europa League marksmen behind German Dieter Muller (29) and Swede Henrik Larsson (31).
Adrian, a promising Spain Under-21 international, weighed in with a goal in the first leg, his seventh of the campaign, and after beating Espanyol 3-1 in La Liga on Sunday Diego Simeone's troops are full of confidence for the second leg at the Mestalla on Thursday.
"We just need more of the same," Simeone, who has revived the club's fortunes since taking over at the turn of the year, said on Atletico's website.
"Obviously this is an important moment for the club, the players and the fans and hopefully we can repeat the same kind of performances we have produced in our last few games," added the former Argentina captain.
Valencia, the 2004 UEFA Cup winners, have never lost a European home match against a domestic rival but were eliminated by Atletico on away goals in the quarter-finals in 2010.
"This is the competition that excites us and all we need is for the players to turn up who did not do so in Madrid last week," Valencia coach Unai Emery said after his side thrashed Real Betis 4-0 on Sunday. "We have to hit our stride and hope that they do not."
The winners of the tie will meet La Liga rivals Athletic Bilbao, conquerors of Premier League champions Manchester United in the round of 16, or Portugal's Sporting in next month's final in Bucharest.
Sporting came from a goal down to win last week's first leg in Lisbon 2-1 and their feisty coach Ricardo Sa Pinto, who took over from Domingos Paciencia in mid-season, has engineered a remarkable revival at the club, injecting new belief and greater tactical discipline.
They successfully disrupted Bilbao's flowing passing game in the first leg and have won six of their last seven matches in all competitions, claiming the prized scalp of Manchester City in the last 16.
"The secret? Work. We foster the values of organisation and attitude," Sa Pinto said after Sporting won 3-2 at Portuguese rivals Nacional at the weekend.
"Attitude is a small thing which can go a long way and make big results happen," he added.
Nicknamed 'Ricardo the lion heart' for his battling spirit as a striker, Sa Pinto had scant experience before taking the job but managed to rejuvenate a demotivated squad.
"We are now a strong team, united and tight-knit and, with the current spirit, we are hard to beat," according to centre-back Daniel Carrico.
"Everyone is rowing in the same direction and now we want to get through the semi-finals."
Bilbao will be without influential midfielder Oscar De Marcos, who is suspended, but are hoping to have Iker Muniain back after the Spain international missed the 1-0 win at Racing Santander at the weekend with an eye inflammation.comments