Northern Ireland manager Michael O'Neill has acknowledged that his side must make improvements after their 1-0 defeat to Poland on Sunday.

The tournament debutants failed to register a shot on target as they left themselves with an uphill task to make the last 16, and ahead of Thursday's meeting with Ukraine, O'Neill has suggested that he could make alterations.

The 46-year-old is quoted by BBC Sport as saying: "There are not many teams in this tournament who will play with two out-and-out strikers so we have to think about that and whether we will change things during the match.

"We have spent most of our time since the Poland match looking at ways of doing things better. The margin between success and failure is so fine. Steven Davis was half an inch from maybe getting an equaliser and that would have put a whole new slant on it."

Ukraine also head into the match without a point on the board after they succumbed to a 2-0 defeat to Germany.