Morecambe midfielder Peter Murphy will miss the rest of the season after suffering cruciate ligament damage.
The 25-year-old has only played eight games in 2015-16, having missed 12 weeks with damaged knee ligaments at the start of the season.
He has also had to recover from a blood clot on his lung.
"An injury like this usually has a six-month rehabilitation programme so he will hopefully back in pre season," said physio Simon Farnworth.
Meanwhile, manager Jim Bentley has confirmed that goalkeeper Tony Thompson has left the club after his short-term deal expired.