The Dallas Mavericks have been doing just fine without Dirk Nowitzki. Now we will see how they do without Shawn Marion. The Mavericks said Tuesday that Marion has a sprained MCL in his left knee and will miss at least three games before being re-evaluated. Marion suffered the injury in the third quarter of Monday’s 114-91 home win over Portland and did not return. Initially, the injury was not believed to be serious. According to the team, Marion had an MRI that confirmed