The Panthers have had a number of their top draft picks coming up through the system during the past few weeks. On Friday, Florida gave one of its former first-round picks away. Defenseman Keaton Ellerby, the 10th overall selection in 2007, was traded to the Los Angeles Kings early Friday in exchange for a fifth-round selection in the upcoming draft. Ellerby left the Panthers team hotel in Washington early Friday morning to join his new team in Detroit. Ellerby could make his debut with the defending Stanley Cup champions against the Red Wings in a nationally televised game Sunday. A healthy scratch Thursday in Philadelphia, Ellerby ended up playing in 125 games over four seasons with the Panthers. Ellerby scored two goals with 15 assists. “Defensemen take time to develop, and sometimes a change of scenery helps someone,” coach Kevin Dineen said after Friday’s afternoon workout in northern Virginia. “When someone leaves your organization, you always wish them well. He was a good-serving Panther, and we hope he takes the full-time step he couldn’t make here. Last year, we couldn’t find a full-time place for him. He’s still a young guy. He has a lot of hockey left in him.’’