New England Patriots safety Rodney Harrison tries to ignore the possibility that his career might be over, and is determined to return from a season-ending knee injury. "I cannot honestly say what's going to happen next year and what the future holds for me in terms of football," Harrison said Friday. "But I'm going to work my tail off to get back on the field." Harrison tore his anterior cruciate ligament, medial collateral ligament and posterior cruciate ligament during New England's 23-20 win over Pittsburgh last month. The Patriots placed him on injured reserve, ending his season. Harrison expects to undergo surgery in about a month, once the swelling in his knee subsides. Meanwhile, the 32-year-old safety is responding well to treatment and therapy. Harrison said he has always recovered from injuries faster than expected. "Now, as far as a timetable, do I know? No, I've never been injured like this before," he said.