Richard Sadlier has been forced to retire from football after failing to recover from a hip problem.
The Republic of Ireland international and Millwall striker, who is only 24, has endured two operations to try and cure the injury but playing football was still too painful.
He told the official club website, www.millwallfc.co.uk: "I just reached the decision that the longer I tried to play, not only was I doing more damage to myself, but the strain was becoming too much - building myself up for each comeback and then being bitterly disappointed when it didn't work out.
"I've been thinking about this for a while, but not seriously until about a month ago. I spoke to the medical people and it just makes sense for me to stop now."
Sadlier scored 34 goals in 103 league starts for Millwall after making his debut six years ago.