The 24-year-old has featured just four times for Liverpool this season.
Agger insists they should have done much better in the Champions League this season.
He said: “You get what you deserve in football and you have to look at closing the game down otherwise you get punished in the way we did in Lyon (when a last-minute equaliser left their Champions League hopes hanging by a thread).
“Now we have just got to look forward to the Birmingham game to get going. If we keep playing with the effort we did in Lyon, we hope the situation will turn for us.”
Liverpool conceded a late goal in the game against Lyon on Wednesday.
Agger added: “It is always so difficult to accept when you lose two points in the manner we did so late in a game.
“We were all so disappointed. We might have controlled the game but it is no consolation; you have got to keep working hard until the last minute.
“But we have to keep believing. We have got to go into the next two games, make sure that we win them and then take it from there.”
