'Show us!' - Bullish Porto goalkeeper Diogo Costa throws the gauntlet down to Arsenal ahead of Champions League meeting

Mikel Arteta's Gunners are widely considered to be among the team's fighting for this year's continental crown, even if the likes of Manchester City and Real Madrid remain the standouts. Arsenal's next test on the path to what would be a maiden Champions League triumph is Portuguese giants Porto. And goalkeeper Costa made it clear that his side will be no pushovers in their last-16 meeting on Wednesday.

The Portugal international told reporters: "They have weak points. Of course, I won't tell you what we are going to do. We will do our best to win the game. If they are the favourites, they need to show us."

Costa's words come amid an incredible run of form for Arteta's side. Arsenal have won their last five games - all coming in the Premier League - scoring a staggering 21 goals and conceding just twice in the process. But Wednesday's fixture could be a case of an unstoppable force meeting an immovable object, as Porto have lost just one game in their last ten across all competitions. Sergio Conceicao's side currently sit third in the Primeira Liga.

Not only are Porto in fine form, but they also boast of significant pedigree in Europe's elite competition. The two-time Champions League winners have reached at least the quarter-finals in three of the last five seasons. Arsenal, on the other hand, have returned to the competition after a seven-year absence, and will look progress to the last eight for the first time since 2010.