Fremantle ruckman Jon Griffin to miss the rest of the season CURSE STRIKES: Fremantle's ruckman Jonathon Griffin lays on the grass at Patersons Stadium clutching his knee. FREMANTLE ruckman Jon Griffin will miss the rest of the season after scans confirmed he ruptured his anterior cruciate ligament against Collingwood last night. Griffin went down in the first quarter of last night's 27-point win over the Pies at Patersons Stadium when his knee buckled during a ruck contest. The 27-year-old was immediately subbed out of the game and his worst fears were confirmed this morning. It is another blow to Fremantle's big man stocks, with main ruckman Aaron Sandilands (hamstring) still sidelined and the versatile Kepler Bradley (knee) out for the season. First-year player Jack Hannath is now the only fit recognised ruckman at Dockers coach Ross Lyon's disposal. He was playing just his third AFL game last night. Fringe ruckman Zac Clarke was supposed to resume from a calf injury via the WAFL next weekend, but now may be rushed straight back into AFL ranks given the club's lack of tall options. Sandilands is edging closer to a return, but is unlikely to be ready for at least another five weeks. Griffin will undergo a knee reconstruction at a time to be confirmed in the coming days. Fremantle football operations manager Chris Bond said the injury was "bitterly disappointing" for the in-form Griffin, who joined Fremantle from Adelaide in late 2010. "Knowing his character and professionalism, Jon will be doing everything that's required through his rehabilitation phase to be back playing footy next season," Bond said.