The drummer from The Fall has been attacked on a train.
Keiron Melling was left with serious head injuries after being beaten and stamped on, and is now recovering at home.
British Transport Police released CCTV images of two men they want to speak to in connection with the attack between Manchester and Blackburn.
In an appeal for witnesses, investigating officer DS Stephen Kite described it as a "horrific assault".
The Fall's manager Ed Blaney has confirmed that Keiron, 34, was the victim of the attack.
Fan site thefall.org has posted an update saying, "very best wishes to Keiron Melling, who bravely stepped in to stop two bullies from picking on a young man on a train near Manchester".
"Apparently Keiron fell asleep on the train and was severely beaten by the two bullies."
The attack happened shortly after 9pm last Monday, on a train travelling from Manchester Victoria to Blackburn.
Two men ran off the train at Smithy Bridge station.
DS Kite from the British Transport Police says: "The behaviour of the two suspects who fled the area makes me believe they are not residents of Smithy Bridge.
"They seemed lost and confused so it is likely they intended to stay on the train until a later destination."