Yuta Watanabe made the opening-day roster for the Brooklyn Nets in the NBA, the Japanese forward said Monday. “Our team has real ability and can aim for the championship. I’ll try my best to be one of their pieces,” said Watanabe, who averaged 5.8 points and three rebounds over four preseason games. The 28-year-old signed with the Nets in late August after becoming a free agent following two seasons with the Toronto Raptors. Since making his NBA debut with the Memphis Grizzlies in 2018, the second Japanese-born player to play in the NBA has appeared in 121 games including eight starts. Watanab…