With an abundance of quality teams in the knockout stage, the 2015-16 edition of the Europa League is receiving a decent amount of media coverage compared to the usual standard, but one result still didn’t get its fair share of attention.

In what was pound for pound probably the toughest draw of the Round of 32, Villarreal dispatched Napoli 2-1 to progress to the last 16, keeping a clean sheet in a 1-0 first leg win at El Madrigal, then coming from behind to draw 1-1 at San Paolo.

That tie felt like a significant statement of intent from the Yellow Submarine. Napoli are currently battling last year’s Champions League runners-up Juventus for the Serie A title, after previously making it all the way to the semi-final stage of the Europa League in 2015.

Beating them was no small feat, and their conquerors must now be considered one of the early favourites to go to St. Jakob-Park on May 18th.

Quietly, Villarreal are mounting a serious assault on Europe.

For anyone who has followed Marcelino’s side closely over the course of this season, their victory over the Italians wouldn’t have come as a huge shock.

Against the big boys in La Liga, the perennial underdogs from Castelló have already proven that they are a force to be reckoned with, beating Atlético Madrid, Real Madrid, and Europa League champions Sevilla in 2015-16.

Holding a defensive record only bettered by Diego Simeone’s Atleti in Spain, they recently managed to string together an impressive 14 game unbeaten streak in the league between early December and March.

There is clear evidence that Marcelino has taken his team up another notch this year, building on the steady work he has done since taking charge of them in 2013.

Back when he first signed up for the job, Villarreal had looked in genuine danger of missing out their goal of an instant return to the top flight following relegation the previous summer. In what proved to be a perfect appointment, the Asturian coach turned the ship around, securing automatic promotion on the final day of the season.

Since then, Villarreal have continued to look up, finishing in the top six in La Liga on two occasions, and they are now clear favourites to go one better and finish in the top four.

They aren’t quite reliving the days when Manuel Pellegrini split Spain’s big two and took them to the brink of a Champions League final, but they are getting closer. Their manager, who has put in place a successful, modern playing style, has been key to the comeback.

In many the style is almost the polar opposite of the possession-based approach of the Pellegrini era. While the Chilean’s Villarreal liked to dominate the ball, Marcelino’s like to dominate space, pressing with a great deal of precision and discipline in order to keep their defence tight.

When they win the ball back, the one-touch passing is explosive and accurate, space again coming into play in the way players seem to be instinctively aware of where their teammate will be making his run. That allows them to move the ball from back to front as quickly and effectively as possible, avoiding the trap of over-using unreliable long-balls that many counter-attacking teams fall into.

If all of that sounds familiar, it’s because it is. Once considered the closest side to Barcelona in La Liga, Villarreal have gradually evolved into the closest side to Atlético.

It is telling that when Marcelino’s men met the Colchoneros on February 21, the two teams effectively cancelled each other out, playing out a 0-0 draw at the Vicente Calderón. Notably, seven of the Yellow Submarine’s 10 wins since December have been by a one goal margin. Simeone would be proud.

Sticking to that disciplines approach has already paid dividends in the league, and if Atlético’s previous success is anything to go by, it could also pay off in Europe.

After all, if Napoli can be kept quiet, then why not Sevilla, Borussia Dortmund or Manchester United? Should Villarreal get the better of Bayer Leverkusen in the last 16, their quarter-final opponents, regardless of their stature, will likely find that the tie is decided on fine margins.

The two games with Leverkusen could mark a significant moment in Marcelino’s tenure. Despite generally solid performances in the group and first knockout stage, he couldn’t take Villarreal beyond the Europa League’s round of 16 last year, where they were unfortunate enough to draw winners Sevilla.

This season could be different. Uncompromisingly solid at the back and clinical when it matters up front, the Napoli tie proved Villarreal are now capable of making an impact on Europe once more. Can they deliver on their potential against the Germans?

Lee Roden is a freelance Spanish and European football journalist. You can follow him on Twitter @LeeRoden89