Dallas Mavericks guard Jason Kidd said he'll consider retirement after this season on Monday.The 38-year-old is in his 18th NBA season and has missed 10 games this season because of injury and fatigue. He's averaging a career-low 5.1 points ger game."My goal was to get to 20 years, but if I can't compete and help a team or help develop a younger point guard then I have to move aside," Kidd said.Kidd also said that it would be great to back up New Jersey Nets guard Deron Williams. New Jersey is moving to a new stadium in Brooklyn next season."I know he'll play 40 minutes so I can give him an eight-minute break. Wherever he ends up- whether it's in Brooklyn or Dallas- that franchise has a great point guard."Kidd, a free agent after this season, told reporters that he'd like to stay in Dallas if he decides to play, or "he'd see" if an opportunity to join Brooklyn presented itself next year.