Boston Celtics head coach Brad Stevens gave fans some bad news on new big man Tristan Thompson.

Stevens told Celtics reporters that Thompson will miss most of training camp due to a hamstring injury, per Tim Bontemps of ESPN.

The Celtics' first preseason game is on Dec. 15 against the Philadelphia 76ers. The team opens the 2020-21 season on Dec. 23 versus the Milwaukee Bucks.

Tristan Thompson signed a two-year, $19 million contract with the Celtics in unrestricted free agency, ending his tenure with the Cleveland Cavaliers. The 29-year-old played nine years with the Cavs. He averaged 9.4 points and 8.7 rebounds in 619 games and was part of the 2016 championship team.

Last season, Thompson put up a double-double for the Cavs before games were suspended in March due to COVID-19. He averaged 12.0 points and 10.1 rebounds per game while shooting 51.2 percent from the field.

The Celtics are hopeful that Double T will be ready for opening night against Giannis Antetokounmpo and the Bucks, who acquired All-NBA defender Jrue Holiday from the New Orleans Pelicans this offseason.

Boston lost to the Miami Heat in the 2020 Eastern Conference Finals in six games at Walt Disney World in the NBA bubble. The Celtics did lose Gordon Hayward to the Charlotte Hornets and traded Enes Kanter to the Portland Trail Blazers. However, Danny Ainge was able to sign Thompson and veteran point guard Jeff Teague. He also gave All-Star small forward Jayson Tatum a lucrative rookie-scale extension worth $195 million.