Houston Rockets center Dwight Howard will get a second opinion on his injured right knee and could miss extended time, league sources told Yahoo Sports.

As the Rockets embarked on a two-game Eastern Conference trip to Boston and Detroit on Thursday, Howard traveled elsewhere to get further evaluation on his swollen knee, league sources told Yahoo Sports.

Because of the injury, it is unlikely Howard can be a candidate for the NBA’s selection process to replace injured Lakers star Kobe Bryant as a Western Conference All-Star reserve, sources said. The All-Star game is Feb. 15 in New York.

Howard has a buildup of fluid in his right knee that has caused the concern. He sat out 11 games earlier this season with a strain in the same knee.

Howard missed the Rockets' past two games, victories over the Lakers and Mavericks, with a sprained ankle.

For the season, Howard has averaged 16.3 points, 11 rebounds and 1.4 blocks for the Rockets.

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