DALLAS — Looking for another shot at the NBA, forward Renaldo Balkman agreed Wednesday to be the 20th and final member of the Dallas Mavericks’ training camp roster.Balkman was the 20th overall pick of the 2006 NBA Draft by New York, and in six combined seasons with the Knicks and Denver Nuggets he averaged four points and 3.5 rebounds in 13.9 minutes per game. Last year Balkman (6-foot-8, 208 pounds) was out of the NBA and played in the Phillippines, Venezuela and Puerto Rico.The Mavs open training camp Tuesday. — Dwain PriceBriefly• Lakers: The club heads into training camp still unsure when Kobe Bryant (mid-April surgery on a torn Achilles tendon) will be on the court this season. • Thunder: General manager Sam Presti didn’t dispute the notion that point guard Russell Westbrook (April surgery to repair torn knee cartilage) could miss the season opener. • Pacers: Paul George signed a six-year extension at between $80 million and $90 million.