However, Rodgers insists that he is happy with his group of players as Liverpool go in search of a place in the Champions League.
"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," Rodgers told the club's official website.
"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.
"It certainly hasn't been because of a lack of work by the football club. 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."
Liverpool are currently fourth in the Premier League.