The Feb. 21 trade deadline is 11 days away. That is an eternity for NBA teams, which historically don’t finalize deals until the final days, hours or minutes. Mavericks vice president of basketball operations Donnie Nelson said Saturday that the level of pre-deadline chatter among teams is “average” for this time of year. Still, it’s been widely predicted that the NBA’s collective bargaining agreement, in its second year, will force teams to shed large salaries, with harsher luxury tax penalties going into effect this summer. Those realties already have forced Oklahoma City to part with James Harden and Memphis to trade Rudy Gay.