Jaylen Brown is unlikely to play Thursday night when the Celtics visit the Wizards.

Boston listed Brown as doubtful for its game against last-place Washington with an illness.

Brown has been the Celtics’ top-billed star this season with Jayson Tatum recovering from Achilles surgery, and he’s excelled in that role, averaging 29.0 points, 6.0 rebounds and 4.8 assists per game while leading a leaner Boston roster to a 12-9 start.

Ranked seventh in the NBA in points per game, Brown topped 40 in two of his last three outings, scoring 41 in a road loss to Minnesota on Saturday and 42 in Tuesday’s win over the Knicks at TD Garden. He also notched his fourth career triple-double Sunday in a win at Cleveland.

Brown ranks second among Celtics players in assists and rebounding behind Derrick White and Neemias Queta, respectively, and he has yet to miss a game this season — a streak that now seems likely to end on Thursday.

The date with the 3-17 Wizards is the first of a back-to-back for the Celtics, who will host the Lakers on Friday in Los Angeles’ annual visit to Causeway Street. The LA tilt will be Boston’s fifth game in seven days.

Brown and Tatum were the only players listed on the Celtics’ latest injury report.