Dirk Nowitzki is a creature of habit. For a dozen seasons, he did things the same way. He worked out in the summer at the same times and usually played his best basketball when the stakes grew late in seasons and in the playoffs. Then the lockout happened last season, and the first knee surgery of his career happened in October. The surgery cost him 27 games, but more importantly, it threw off his routine and he said Sunday he’s been fighting through that ever since. He said there is no truth to any speculation that his surgery required more than a basic cleaning up of debris in the joint after a lifetime of running, jumping and pounding. “After 15 years, there’s going to be some stuff in the knee,” Nowitzki said. “And they had to clean it out. The major thing, I thought, is that the doc actually said that for a knee that’s been pounded on for 20 years jumping, it looked really good. There’s still some cartilage in there. There are some players in this league that are bone-on-bone. “So that’s a good thing that there’s some left.” But after missing 27 games, Nowitzki needed another 10 or so to go through what would normally have been training camp and preseason games. “I don’t know why, really, the recovery took so long with me,” he said. “Mainly, it was because of the swelling at the beginning. It was my first knee surgery ever and the swelling stayed a good two, three weeks and that really put me way behind the 8-ball. I couldn’t start working out until almost a month in or even longer than that. I guess the swelling messed me up.”