FC Porto goalkeeper Diogo Costa says Arsenal have weaknesses, and the Gunners still need to prove themselves as one of the Champions League favourites.

Arsenal are set to face FC Porto on Wednesday night, and Porto goalkeeper Diogo Costa spoke to the media on Tuesday about the last-16 Champions League tie.

Costa wasn’t keen to give Arsenal too much encouragement, insisting the Gunners have weaknesses, and they still need to prove themselves.

“Of course [Arsenal] have weak points,” Costa said. “Of course, I’m not going to tell [you] what we’re going to do. We’re going to do our best job to win that game.

“If they are [one of] the favourites (to win the competition), they need to show us they are the favourites.”

Looking at the situation and Costa’s comments objectively, it’s fair to say they aren’t too out of line.

Though Arsenal had a very strong group stage, winning the group with a game to spare, the knockout stages are a very different proposition.

The Gunners even had their slip-ups in the group, notably losing away to Lens. Another result like that in Porto may not be so easy to salvage, with the pressure on.

Mikel Arteta’s side have been on an excellent run lately, winning all five of their Premier League fixtures since the winter break.

But it wasn’t too long ago the manager was reflecting on three straight defeats to West Ham United, Fulham, and Liverpool. The team clearly have some weaknesses.

If Arsenal really want to be one of the favourites to win the Champions League, they need to use comments like Costa’s as motivation to push on and show they deserve to be in that conversation.