The Hoops take on Rosenborg in their opening Europa League fixture on Thursday.
After just five goals in five league games, including a blank against St Mirren, Rogers encouraged his team to have more of a killer instinct.
"On paper we have lots of players that can score but you don't win the game on paper," said the Northern Irishman, who revealed Kristoffer Ajer is a big doubt with a virus while fellow defender Jozo Simunovic remains out with a knee injury.
"You have to win it on the field. We have to take those opportunities.
"I have always said possession is no good on its own. We have to have that penetration.
"But we have to be more demanding of ourselves now. That is our message.
"My trust in the players is 100 per cent, they have been brilliant in the time I have been here.
"But we need to improve in the final third of the pitch. Defensively we have been solid in our last four games, keeping a clean sheet, but we need to do more in the attacking third of the pitch.
"It is ensuring we have that energy and quality and being clinical to take opportunities.
"That is something that we have talked about and focused on in our training and will look to bring in these next games."