But Brendan Rodgers and his players were left to reflect on whether the evening might have panned out differently had their on-loan Borussia Dortmund full-back Jeremy Toljan not been sent off eight minutes from the end of a first half in which the Scottish champions had hinted at the possibility of recording their first ever victory in Spain.
The second of the yellow cards Toljan picked up in quick succession from his German compatriot, referee Deniz Aytekin, was certainly of the contentious variety. It fatally undermined Celtic’s admirable attempt to somehow overturn their 2-0 first leg deficit.
French striker Gameiro, a four-time Europa League winner with Sevilla and Atletico Madrid, struck just two minutes after his introduction from the bench to wrap up Valencia’s place in the last 16 draw.
In seeking a change of fortune for Celtic on Spanish soil, there was a change of shape from Rodgers. His team were deployed in a 5-4-1 formation, with Toljan and Jonny Hayes either side of a three-man central defence, which was intended to switch fluidly to a 3-4-3 whenever the visitors had attacking possession.
It was a strategy which worked encouragingly well until the dismissal of Toljan scuppered Rodgers’ best laid plans. Before Toljan’s departure, Celtic passed the ball with composure and accuracy on the slick Mestalla playing surface. Hayes, in particular, had plenty of scope to push forward and he provided the first evidence of his team’s belief the tie was far from over.
Surging down the left in the fourth minute, Hayes jinked his way beyond a couple of challenges before drilling in a low cross-cum-shot which Valencia ‘keeper Neto held confidently.
More enterprising play from Hayes six minutes later saw him force a corner which Ryan Christie swung in to the edge of the six yard box. The ball fell for Kristoffer Ajer whose first shot was blocked by Daniel Wass before he blazed his follow-up attempt off target.
As heartened as Rodgers would be by the manner of his team’s approach, he would have been alarmed by the slackness which presented Valencia with their first real opening. The Celtic boss had stressed the need to cut out the unforced errors which proved so costly in the first leg but Dedryck Boyata was guilty of exactly that in the 16th minute.
The Belgian defender’s underhit pass was pounced on by Ruben Sobrino who raced clear down the right but, to Celtic’s relief, was unable to pick out Goncalo Guedes with his cross.
Oliver Burke, so often an isolated figure for Celtic in the first leg, found more opportunities here to test the Valencia defence with his pace. The on-loan West Brom forward caused real alarm in the home ranks with a sprint into the penalty area where his shot was blocked by Ezequiel Garay. The Valencia defender’s effort to cover Burke’s break came at the cost of what looked like a hamstring injury and he was replaced by Francis Coquelin.
Toljan’s fateful first yellow card came in the 26th minute as a consequence of another short pass from Boyata which left the full-back with little option but to pull back Lato as the Valencia player pounced on the error and was poised to race clear into the penalty area.
Boyata’s moments of poor concentration aside, Celtic remained compact and progressive. Another raid from Burke saw him lay the ball back for Christie whose shot was deflected wide by Carlos Soler.
James Forrest then carved out space on the right to float over a cross which found its way to the unmarked Hayes at the far post. It was Celtic’s clearest sight of goal yet but Hayes sliced his left foot shot wide of Neto’s right hand post.
The home fans were becoming increasingly disgruntled by their team’s display but Celtic’s hopes of building on the promising pattern of the match from their perspective diminished when Toljan received his second yellow card eight minutes before the interval, again found wrong side of his opponent as he stopped a burst forward by Guedes.
Celtic reshaped themselves into a 4-4-1 formation but Valencia stepped up the tempo and Scott Bain had to make two excellent saves to keep the scoreline goalless at half-time. The Celtic ‘keeper changed direction with supreme alertness to touch over a shot from Daniel Parejo which took a deflection off Brown, then denied Santi Mina’s powerful shot with an equally impressive one-handed save.
Valencia were very much in the ascendancy at the start of the second half and, as they built up a head of steam, Jozo Simunovic had to clear off the line after Mina cut in from the left and stabbed the ball beyond the advancing Bain.
Celtic were understandably finding it far more difficult to engineer attacking situations but they should have given themselves a glimmer of hope in the 62nd minute. Christie’s free-kick from the right picked out Ajer on the edge of the six yard box but the Norwegian international spurned a glorious chance as he headed over.
Eight minutes later, any lingering prospect of an unlikely salvage job from Celtic evaporated when Valencia broke the deadlock on the night and extended their aggregate lead. Gameiro, who had only just replaced Sobrino, got on the end of a cushioned header into his path from Wass and while his shot wasn’t the cleanest he has ever struck, it was sufficient to find a way through Bain.
VALENCIA: Neto, Wass (Lee 76), Garay (Coquelin 23), Diakhaby, Lato; Torres, Soler, Parejo, Guedes; Sobrino (Gameiro 68), Mina. Subs not used: Domenech, Cheryshev, Gaya, Centelles.
CELTIC: Bain, Toljan, Boyata, Ajer, Simunovic, Hayes; Forrest (Edouard 63), McGregor, Brown, Christie; Burke (Johnston 73). Subs not used: Gordon, Izaguirre, Sinclair, Lustig, Weah.