In 1968, United won the European Cup for the first time, but Law's knee injury was causing him serious problems and he missed both the semi-final second leg and the final as a result. He was regularly given cortisone injections to ease the pain, but playing while the knee was still injured was causing long-term damage. He visited a specialist in January 1968 who wrote to United claiming that a previous operation to remove the cartilage from the knee had failed and recommending that a second operation be performed, but Law was not shown the report for several years and had to continue full training.