Tranmere winger Adam McGurk is set to be out for the next four to six weeks after suffering a collapsed lung overnight on Thursday.
McGurk, who was already set to miss Rovers' weekend trip to Colchester with a hamstring injury, has been struck down by a pneumothorax and a statement on the club's official website explained the nature of his condition.
"Lungs are lined with a double layer of membrane, the inner one covering the surface of the lung and the outer one covering the inside of the chest wall, separating the lung from the chest wall.
"A pneumothorax occurs if air gets between these two layers. Once air is drawn into this space, it cannot easily escape and the air compresses the lung and interferes with breathing.
"This makes the lung collapse, making breathing difficult. Adam has had the air drawn out and will be allowed to rest while his body recovers.
"His training will then be gradually increased, initially beginning with non-contact before he eventually rejoins full training."
McGurk has made 28 appearances for Tranmere this season, scoring four times.