Rodgers insists his squad is good enough to meet their targets this season.
"I think it's difficult in order to bring certain players in that are going to help us immediately. The availability of the player, and of course the affordability, are always the two factors involved in getting a player in. It certainly hasn't been because of a lack of work by the football club," he said.
"There are lots of people who have worked tirelessly to identify and find the right types of players. A lot of those players haven't been able to become available for us. Of course, as a manager, you would like to have strengthened - but I'm very optimistic with the group of players I still have available here. If we can keep those players fit, and maximise the availability for the rest of the season, we can have a great chance to have a really good finish."