Damian Lillard has entered concussion protocol, the Milwaukee Bucks announced Monday night. He will miss Tuesday’s matchup with the Toronto Raptors.

Lillard, 34, suffered a hit to the head during the third quarter of Sunday’s 113-107 loss to the Boston Celtics, according to reporter Chris Haynes. He scored 14 points with six assists and four rebounds in 36 minutes of play.

However, Lillard experienced headaches and dizziness on Monday and tests confirmed that he sustained a concussion. He is listed as out on the team’s injury report, but could possibly be available for Wednesday’s game against the Detroit Pistons.

In Milwaukee’s 10 games this season, Lillard has averaged 26 points and 6.6 assists per game. However, the Bucks have been one of the disappointments of the early season at 2-8. That’s the second-worst record in the Eastern Conference, just ahead of the 2-9 Raptors. The two teams will play in Tuesday’s opening game of group play in the NBA Cup tournament.

Lillard played in 73 games last season, his highest total since the 2018-19 campaign with the Portland Trail Blazers. Yet in the playoffs, he missed two games of the Bucks’ first-round series against the Indiana Pacers with.a strained right Achilles tendon.

The Bucks have been without All-Star forward Khris Middleton, who had surgery on both of his ankles and has yet to play this season.