IT WASN'T the biggest hits from his arch-enemy St George Illawarra that floored Lance Thompson, nor the training drills under coach Ricky Stuart at his latest club Cronulla. It was the exuberance of his seven-year-old daughter, Shalisse.

Thompson, 30, was kicking a soccer ball with Shalisse shortly after playing the Dragons a fortnight ago and he could barely keep up with her - his shredded knee, which he had nursed through the off-season and during a couple of games in the NSW Cup - was giving him agony.

Recalling the moment he realised his playing days were over, Thompson nearly broke down yesterday: "Retiring will give me the chance to deal with my injuries and with my diabetes, and I will also have time to watch my daughter grow up. It has been a hard six months getting my knee and health right, and I knew it was time to retire from this great game."

Thompson consulted medical staff for a second opinion but deep down he already knew the answer. His knee has no meniscus, and bone is rubbing on bone. It is the same injury that befell Laurie Daley, but he didn't have the added complication of daily insulin injections on top of cortisone and painkillers. Doctors told Thompson he had "one game left in him". Stuart insisted it be at the club's home ground, Toyota Park, as a mark of respect to the enthusiastic clubman.

"One of the hardest days in football is to retire," Stuart said.

"It is like someone takes away your favourite toy, your favourite gift away from you, and you have to lead a new life."

Thompson's departure leaves a gaping hole in the Sharks second row, with the club having already lost Reece Williams for the season with a knee reconstruction. Stuart is looking at some of his backs, such as Dustin Cooper and Fraser Anderson whom he will groom to move into the pack, but it will be Thompson's vitality and rousing play that will be most missed.

"I have played with and against many tough players but none of them are tougher than 'Thommo' - none could sustain what he endured," Stuart said.

Thompson, who played six City Origin representative games, will formally hang up his boots after celebrating the opening of the $10 million upgrade of Shark Park when the Sharks play the Penrith Panthers on Saturday night.

The Shire faithful have embraced Thompson ever since he was discarded by the St George Illawarra Dragons at the end of 2005, and he has never disappointed with his barnstorming runs. The planned farewell, including a lap of honour, will be memorable.