Fremantle midfielder Matt de Boer celebrates his first win over Collingwood Fremantle's Jonathon Griffin has picked up a season ending knee injury in his side's clash with Collingwood last night, while Pies pair Marty Clarke and Quinten Lynch suffered less serious injuries. Matt de Boer celebrates Fremantle's win over Collingwood with teammates Danyle Pearce and David Mundy. FREMANTLE midfielder Matt de Boer has described Saturday night's win over Collingwood as one of the best of his 83-game AFL career. The 27-point win -- without skipper Matthew Pavlich, ruckman Jon Griffin and midfielders Nat Fyfe and Stephen Hill -- was the first time de Boer and many of his Dockers teammates have celebrated a victory over the Pies. "It definitely mean a lot, but just to have a good character win in front of our home crowd was really satisfying" de Boer said, It gives us belief in our game plan that if we bring great effort, we can get the job done. However, the win came at a cost as another key player's season came to a crushing end. Ruckman Jon Griffin will have a knee reconstruction in the coming days after going down in the opening minutes of Saturday night's game. The Dockers are already without versatile big man Kepler Bradley (knee) for the rest of the season and Sandilands (hamstring) is not expected to resume for at least another five weeks. Zac Clarke (calf) will also need a few WAFL matches under his belt before he can play at AFL level. First-year player Jack Hannath, 21, stepped up in just his third AFL game after Griffin went down and will be asked to lead the ruck brigade against Sydney at the SCG on Saturday night. Alex Silvagni, Michael Johnson and Zac Dawson are also likely to be used as pinch-hitters in the ruck. "We're testing our depth, but it's great that anyone who comes in, we know they are going to fulfil a role and bring great effort," de Boer said. These kids come in and they're raw, but they're so keen to play and impress. Jack's been really good and he'll have to step up again. De Boer said coach Ross Lyon had encouraged his team to celebrate the win over Collingwood, but had also warned his charges not to get too carried away with the victory ahead of the clash with Sydney. Fremantle will welcome back Fyfe from suspension, while Hill will be considered despite missing a second straight match with a quad complaint.