(Reuters) - The injury-plagued Boston Celtics suffered another setback when guard Leandro Barbosa was declared out for the rest of the season with a torn left anterior cruciate ligament, the National Basketball Association team said on Tuesday.

The Brazilian sustained the non-contact injury late in the third quarter of Monday's loss to the Charlotte Bobcats.

For Boston, it was the third season-ending injury in less than three weeks.

Rajon Rondo tore his right ACL on January 25 in Atlanta and rookie Jared Sullinger left in the first quarter of a game against Sacramento five days later due to back spasms and required lumbar disk surgery.

The 30-year-old Barbosa averaged eight points, 2.8 assists and 2.4 rebounds over 21.3 minutes per game in eight appearances since Rondo was lost.

Despite the rash of injuries, Boston (27-24) had been riding a season-high seven game winning streak after Rondo was lost before losing to the Bobcats on Monday in the second night of a back-to-back.

(Reporting by Larry Fine in New York, Editing by Gene Cherry)