Both members of the Portland Trail Blazers' starting backcourt are now dealing with injury issues. Damian Lillard is already sidelined with lower abdominal tendinopathy, and now CJ McCollum will be out indefinitely with a pneumothorax that he suffered in Portland's game against the Boston Celtics over the weekend, the Blazers announced on Tuesday. In layman's terms, a pneumothorax is a collapsed lung, which can be a very serious issue. 

Here's the official statement from the team: 

Upon further examination, a CT scan revealed that Trail Blazers guard CJ McCollum has a pneumothorax (right lung), the team announced today. McCollum sustained the injury during the 4th quarter of Portland's game versus Boston on December 4. He will be further evaluated before a prognosis is determined and his status will be updated accordingly. McCollum did not travel with the team for Wednesday's game at Golden State.

In 24 games this season (all starts), McCollum has averaged 20.6 points (42.4% FG, 39.3% 3-PT, 70.0% FT), 4.1 rebounds, 4.5 assists, 1.08 steals and 35.3 minutes.  

McCollum's health is obviously the main concern, but the injury is also a big blow for the Blazers, who are already struggling to remain in the crowded Western Conference playoff picture. Portland currently resides in the 10th seed with an 11-14 record. Without Lillard, and now McCollum, they'll run the risk of slipping down the standings. Keeping the team afloat will be a tall task for first-year head coach Chauncey Billups. 

More information regarding McCollum's status will likely be provided by the Blazers in the near future.