Still in search of their first win of the season, the Boston Celtics will be without one of their best players Sunday night against the Houston Rockets.

Jaylen Brown -- who celebrates his 25th birthday Sunday -- has been ruled out of the game due to left patella tendinopathy.

Brown scored a career-high 46 points in Boston's season opening 138-134 double-overtime loss to the New York Knicks Wednesday, also setting a record for most points scored in an opener for the Celtics, but struggled mightily in the team's loss to the Toronto Raptors in Friday's home opener.

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In 28 minutes, Brown finished with just 9 points on 3 of 13 shooting, failing to connect from 3-point land in seven attempts.

The Celtics are facing a 1-1 Rockets team coming off its first win of the season, a 124-91 rout of the Oklahoma City Thunder on Friday.