He was expereinceing concussion-like symptoms and evaluated before the team's flight to Boston on Saturday.
Kevin Love is in concussion protocol and is listed as out for Game 7 after suffering a head injury Friday, the team announced.
Love left Friday's Game 6 of the Eastern Conference finals following a head-to-head collision with Boston's Jayson Tatum.
He was experiencing concussion-like symptoms and evaluated before the team's flight to Boston on Saturday.
Around five minutes into the game, Tatum ran into Love while the Cavaliers forward was setting a screen and the contact forced Love to the ground and made Cleveland commit an intentional foul so he could get off the court.
Through the first five games of the series, the five-time All-Star was averaging 15 points and 11 rebounds in 31 minutes of action. On Friday, he had four rebounds and went 0-for-3 from the field in his limited time on the court.
Game 7 will take place Sunday in Boston at 8:30 p.m. ET. If the Cavaliers win, it will send them to their fourth consecutive NBA Finals.