The Portland Trail Blazers announced that guard CJ McCollum has a pneumothorax (collapsed right lung), which he suffered during the team's game against the Boston Celtics on Tuesday.

McCollum will undergo further evaluation before a prognosis is decided, per the team. At that point, his status will be updated.

The former Lehigh University star has averaged 20.6 points, 4.1 rebounds, 4.5 assists and 1.1 steals in 35.3 minutes this year.

The Mayo Clinic defines a pneumothorax as follows: "A pneumothorax occurs when air leaks into the space between your lung and chest wall. This air pushes on the outside of your lung and makes it collapse. A pneumothorax can be a complete lung collapse or a collapse of only a portion of the lung."

McCollum did not travel with the Blazers for their road game against the Golden State Warriors on Wednesday, per the team. Following that matchup, the Blazers will have three days off before returning home to face the Minnesota Timberwolves on Sunday.

Initial reports on Sunday indicated that McCollum suffered bruised ribs. Chris Haynes of Yahoo Sports tweeted Sunday that X-Rays came back negative and that he would be re-evaluated Monday.

McCollum was then listed as probable for the Blazers' game against the Los Angeles Clippers on Monday with a rib contusion, but he was downgraded to out.

The shorthanded Blazers have lost three in a row to drop to 11-14. They are now without their entire All-Star backcourt of McCollum and Damian Lillard, who has missed the team's last four games with lower abdominal tendinopathy.

Four other players (Anfernee Simons, Nassir Little, Cody Zeller and Ben McLemore) are listed as questionable for the Warriors game with various injuries.