Arsenal cruised through to the semi-finals of the UEFA Europa League after their 4-0 demolition of Slavia Prague on Thursday night - setting up a showdown with their former boss Unai Emery.
Villarreal defeated Dinamo Zagreb 3-1 on aggregate to book their place in the last four of the competition and their upcoming clash has an added spice to it given Emery was sacked just 18 months into his Gunners tenure.
The two sides meet on April 29 at El Madrigal, with the second leg scheduled to take place a week later at the Emirates Stadium on May 6.
Mikel Arteta might have won a trophy with Arsenal at the back end of last season but the pressure is on him to salvage what's undoubtedly been a disappointing campaign so far. Standing in his way is his predecessor so which of them will reach the final in Gdansk?
Arteta vs Emery
All the talk in the lead up to this one will be largely centred around Unai Emery and his return to the Emirates Stadium as an opposition manager.
The 49-year-old boasts an impressive record in this competition having won it three seasons running during his time in charge of Sevilla. Despite the difficulties he had at the Emirates Stadium, he managed to guide the Gunners all the way to the 2019 final where they were beaten by their Premier League rivals Chelsea.
Mikel Arteta has shown some signs of promise in the early days of his managerial career but in terms of experience at the highest level - Emery is the clear winner. The Villarreal boss has always remained respectful towards his former club but there's no doubt he'll be relishing the opportunity to exact revenge on his former employers and what better stage to do it on than the semi-finals of his cup.
It's unknown if Pierre-Emerick Aubameyang will return to action in time to play a part in both legs of this semi-final but Alexandre Lacazette proved in Prague that he is more than capable of stepping up in the absence of his captain. Since a switch of system just after Christmas, Arsenal have shown far greater balance in their play and it has seen their overall game improve even if results haven't always reflected that.
Lacazette is the club's top goalscorer this season having netted on 17 occasions, closely followed by Aubameyang with 14. Nicolas Pepe has also chipped in with a respectable tally of ten and the Gunners' creativity nowadays comes mostly through Bukayo Saka, Emile Smith Rowe and loanee Martin Odegaard.
Gerard Moreno is Villarreal's leading goalscorer and by quite some distance. The 29-year-old has netted an impressive 25 times in 35 appearances this season and is by far the Spaniards' biggest goal threat. Paco Alcacer, the former Barcelona and Borussia Dortmund striker is another player to watch out for but outside of their centre-forward options, Villarreal struggle for goals from other areas of the pitch.
Both sides have shown signs of defensive improvement under their current managers but neither can boast being an impenetrable unit.
Villarreal's defence includes Spurs loanee Juan Foyth and former Real Madrid star Raul Albiol, while former Premier League players Ramiro Funes Mori and Alberto Moreno are also part of Emery's set-up. Etienne Capoue, formerly of Watford, regularly plays as a defensive midfielder, too.
The Gunners will be without two of their first-choice back four in David Luiz and Kieran Tierney through injury. Although they coped just fine in Prague on Thursday night, Arteta will certainly wish he had a full squad to choose from for such a big game.
The last time Arsenal met Villarreal at the semi-final stage in a European competition was way back in 2006. Jens Lehmann saved Juan Roman Riquelme's last minute penalty to ensure the Gunners progressed through to the final.
Given it was such a long time ago, that meeting will have no bearing on what unfolds in the next few weeks but it's a game that will not have been forgotten by either set of fans.
This is the third time in four seasons Arsenal have reached the semi-final stage of the competition, meaning in recent history they have the superior record. But in Unai Emery, they face a three-time Europa League winner and that goes some way in closing the gap between the two sides.
The La Liga side have won four of their last five fixtures in all competitions whereas Arsenal have won just two of their last five.
Both sides have games to play ahead of the first leg and things could still change by the time they lock horns at the end of the month. That emphatic victory in Prague will do the Gunners the world of good though in terms of their confidence.
When it comes to identifying Arsenal's weaknesses, very few understand them better than their former boss. Arteta has made plenty of changes since taking the reins at the Emirates Stadium but Emery worked with many of the current group and will be hoping to use his inside knowledge as he plots their downfall.
Neither side is competing at the top of their respective leagues and therefore it is likely, having reached this stage, the Europa League will take precedent for both managers.
Arsenal should have enough to squeeze through to the final but it'll almost certainly be a very tight contest. If the Gunners aren't at their best, Villarreal pose a serious threat and are more than capable of eliminating the Londoners.