When Liverpool fought so hard to keep Daniel Agger this summer, it was expected he’d play a major part this season. Through the first half of the campaign, however, Agger gone from automatic starter, relegated to the bench, to back in the rotation within the span of five months. Yet after this weekend’s FA Cup game against Oldham Athletic, the Danish international is back on uncertain ground, a calf injury threatening to undermine the progress he’s made to get back into Brendan Rodgers‘ team. Agger was forced to leave Sunday’s 2-0 and underwent tests on Tuesday to help diagnose the injury’s extent. With four other defenders already hurt, Liverpool was thin in defense before Agger’s injury, a state that forced the Danish international to make three starts in eight days after going off versus Oldham.