The Mavericks have taken three swings at the Thunder this season. Twice they lost in overtime and last month they were hammered by 21 in Oklahoma City. This qualifies as a high-quality win if the Mavericks can snag it, since the Thunder is fighting San Antonio for the top record in the Western Conference. “They’re tough, one of the best in the league,” Nowitzki said. “We wish we had (Shawn Marion). He’s our best defender. But it looks like he’s going to be out. (We have to) try to make it hard on Westbrook and Durant.”