The Boston Celtics lock horns against their Eastern Conference rivals, the Washington Wizards, on Thursday. Ahead of their contest, the Celtics received a concerning update on Jaylen Brown's health, who was listed as doubtful on the team's injury report after Wednesday's practice. Brown is dealing with a non-COVID illness, which has put his availability in danger.The veteran forward led the Celtics to a fantastic 123-117 win over the New York Knicks on Tuesday. The one-time Finals MVP dazzled with a spectacular performance, putting Boston on his back and leaving Madison Square Garden with a thrilling victory.Brown finished with a season-high 42 points on 16 of 24 shooting, including 2 of 6 from beyond the arc. He also recorded four rebounds, four assists and one steal in 40 minutes.The Celtics forward's performances have flown under the radar. He has Boston at 12-9 with a roster that everyone wrote off when the season tipped off. The four-time All-Star has put up MVP-level numbers, averaging 29.0 points, 6.0 rebounds, 4.8 assists and 1.1 steals, while shooting 49.9%, including 34.7% from deep.The Celtics have won seven of their last nine games and climbed to sixth place in the East. Jaylen Brown has recorded five games with at least 30 points in that span.Meanwhile, Jayson Tatum is the other Celtic on the injury report. The franchise's poster boy remains sidelined with a right Achilles injury.How to watch Boston Celtics vs. Washington Wizards?The Boston Celtics vs. Washington Wizards game will take place on Thursday at the Capital One Arena in Washington, DC. Tip off is slated for 7 p.m. EST.The Celtics vs. Wizards game will be telecast live on NBC Sports Boston (local) and Monumental Sports Network (local). Live streaming will be available on the NBA League Pass and Fubo TV app and website (regional restrictions may apply).