The Nets signed center Jason Collins for the remainder of the season this morning, locking in another piece of the roster as they head toward the postseason. Last month, Collins became the first openly gay competitor in the history of the four major American sports when he signed a 10-day contract with Brooklyn. In his 20 days with the Nets, Collins has averaged less than 10 minutes per game and scored a total of only three points. On March 5, Collins signed a second 10-day contract. When that contract expired just before midnight Friday, the Nets had to decide to keep Collins for the remainder of the season, or release him; players can only sign two 10-day contracts with a team in a single season. Brooklyn decided to keep him, because of his interior defensive presence, his leadership and his postseason experience. “He’s been to the Finals twice,” said Nets coach Jason Kidd, who along with Collins won Eastern Conference titles for New Jersey in 2002 and ’03. “He understands that time of year.” The 35-year-old 7-footer known as “Twin” is regarded as a smart, tough player who makes opponents pay for entering the paint. Along with 37-year-old Kevin Garnett, Collins has been providing leadership for the Nets younger big men, including rookie F/C Mason Plumlee. “[Collins] and [Garnett] can help Mason understand a lot of different things on how to get better,” Kidd said. “Twin can help him understand what it means to foul. There’s a technique I guess in that. But I think it was a good signing all around and I think it helps Mason.” Collins is jokingly referred to as a “professional fouler” by his teammates. He is averaging 11.1 fouls per 48 minutes this season, making him one of the most frequent fowlers in the league. But he also leads the league in something else: jersey sales. reported last week that since Collins No. 98 jersey went on sale in late February it has been the top-seller on LeBron James, the most famous player in basketball, is second.