Lionel Messi
Lionel Messi celebrates after scoring one of his four goals for Barcelona against Arsenal in the 2010 Champions League quarterfinals. Getty Images

It just had to be. Arsenal have an unfortunate habit of paying the heaviest price for finishing runners-up in the Champions League group stage, and on Monday that pattern continued. This time around they were paired with a Barcelona team that romped all before them en route to lifting the European Cup last season, and have continued to wow this campaign.

It will be the third time in seven seasons that Arsenal will come up against Barcelona in the Champions League knockout phase, with the Catalan giants having come out on top on the two previous occasions. And it was the same story in Arsenal’s only trip to the final of the competition, in 2006, when Barcelona came from behind to crush the hopes of Arsene Wenger’s men. Add that history to the fact that Arsenal have exited the Champions League at the Round of 16 for the last five seasons, and the omens are certainly not good.

Here are four factors that could be key to deciding which team makes it onto the quarterfinals.

Barcelona set to be even stronger
Barcelona swept through the group phase undefeated and also sit top of La Liga. As if that weren’t worrying enough for Arsenal, there is every reason to believe Luis Enrique’s side will be even stronger when the Round of 16 matchup arrives in February and March. Barcelona have been riding out a wave of injuries in the early months of the season, including the absence of Lionel Messi for two months. Not only are those injuries now clearing up, but the squad will be boosted in January when summer signings Arda Turan and Aleix Vidal will finally be eligible to play, following the conclusion of the club’s transfer ban. That will bring real strength in depth, with the possibility existing that Barcelona could even enter the transfer market again next month.

How healthy will Arsenal be?
Given the consistently long list of injuries that have besieged Arsenal in recent seasons, any analysis of their prospects must come with the caveat of wondering just how healthy they will be when the Round of 16 arrives. Already Santi Cazorla appears highly unlikely to feature in either leg, while Francis Coquelin is a major doubt, certainly for the first leg. The loss of Coquelin would be a particular blow, given his discipline sweeping up in front of the defense, and there is likely to be even more pressure on Wenger to sign an alternative in January. Still, there is some encouragement for Arsenal. The squad has shown in recent weeks that it perhaps has more depth than in the past. Notably, they were without several players when getting a 3-0 win at Olympiakos to take them into the last 16.

Barcelona’s forward trio unstoppable?
Can Arsenal stop Messi, Neymar and Luis Suárez ? Can anyone stop them? Luis Enrique has called his front three the greatest in history, and it would be hard to disagree. They set records with their goalscoring feats last season, and, if anything, they have only improved this campaign. Each with the ability to destroy an opponent single-handedly, they also have an incredible and selfless chemistry. History provides little encouragement that Arsenal have what it takes to stand in their way. Messi tore through Arsenal in the second leg of the sides’ quarterfinal in 2010, scoring four goals. Suárez has also provided Arsenal nightmares, notably in Liverpool’s 5-1 destruction of Wenger’s side in February, 2014. The Uruguayan’s wonderful ability to run in behind defenses will be a particular challenge to an Arsenal side that can still be caught out on the break and has the lack of pace of Per Mertesacker in defense.

Will Wenger alter Arsenal’s approach?
In the previous matches with Barcelona, and indeed in almost every game for a number of seasons, Wenger’s approach was that, no matter the quality of Arsenal’s opponents, his side would go toe-to-toe with them. There was very little attempt made to stifle the opposition’s threats, rather a purist’s obsession with simply trying to outplay them. But there have been signs in the last year or so that the veteran manager has acknowledged that such an approach has led to some chastening defeats and contributed to a long wait for major silverware. There is now a greater willingness to sit back and strike on the counter attack against the very best teams. And there is evidence that such a plan could reap some rewards against Barcelona. On Saturday, Deportivo La Coruna employed such tactics in earing a 2-2 draw at the Camp Nou. One problem, though, could be that the first leg of the Round of 16 clash will be at the Emirates Stadium. Will Wenger truly be willing to sacrifice his team’s proactive instincts in front of their own fans and on such a big stage?

First leg: Tuesday, Feb, 23, 2016, at the Emirates Stadium
Second leg: Wednesday, March 16, 2016, at the Camp Nou