Justin Blumfield will be sidelined for up to a month after an MRI scan late this afternoon revealed he had a grade one tear of his posterior cruciate ligament in his right knee. It was bittersweet news for the Bombers who will sorely miss the classy mid-fielder. But the damage to the ligament could have been much worse and four weeks on the sidelines was the best the club could have hoped for. Blumfield will undergo arthroscopic surgery tomorrow morning making him the fifth Bomber to undergo such surgery this season. Mark Mercuri, Joe Misiti, Steven Alessio and Michael Long have all had arthroscopes this season.

Blumfield's injury is similar to that suffered by Joe Misiti against Carlton in round three this season. Misiti also damaged his posterior cruciate ligament but it was diagnosed as a grade three tear - far more severe than that suffered by Blumfield. Misiti is not expected back until round 12.

Blumfield suffered the injury in the first quarter against Hawthorn and after leaving the ground took no further part in the game.