Northern Ireland defender Jonny Evans has acknowledged that the European Championship debutants failed to play to their strengths in their opening game against Poland.
Michael O'Neill's team failed to register a shot on target as they succumbed to a 1-0 defeat to Poland, and ahead of their clash with Ukraine, Evans has said that his side must improve in order to give themselves a chance of making the last 16.
The 28-year-old told reporters: "Looking back at the game, there are things that we didn't do that we are good at and we want to get back to that, like closing people down and competing more than we did in the game.
"We need to me more physical and aggressive and stamp our authority on the match. We have watched the videos and I think the players will look back on that and see that. It's like another cup final for us.
"Lots of teams have lost their first game and the beauty of this tournament and the format going forward is that we have all got a chance of still qualifying."
Northern Ireland are likely to have to beat either Ukraine or Germany in order to progress through to the knockout stages.