Dallas Mavericks All-Star forward Dirk Nowitzki admits that his drive dwindled after winning an NBA Championship last year.Nowitzki, who had to take a week off this season to get into game shape, told SI.com that his “motivation was gone for a little bit” after winning the NBA title, leading to his poor preparation for the lockout shortened 66-game schedule.“Now I reached both goals, and it was just hard in the beginning,” he told reporters. “The Euros came too quick, right after the [NBA] championship. I only had, like, a month off. I needed more time to get away and enjoy the championship. If I would have had a couple months off to enjoy it, party, get everything out of the way, then start slowly back up — that would have been the way to go. But I decided to play, to try my best, and we didn’t qualify, unfortunately.”Nowitzki is averaging 19.6 points per game this season – the lowest scoring average of his career. He averaged 23 points per game last season.