Boston forward Danilo Gallinari suffered a torn ACL in his left knee while playing for the Italian national team, the Celtics announced Friday, an injury that could cause him to miss the entire 2022-23 NBA season.

Gallinari previously tore the same ACL in April 2013 and missed the entire 2013-14 season after undergoing a pair of surgeries. The typical recovery time for an ACL tear is six to 12 months, and a source told ESPN's Adrian Wojnarowski that Gallinari is determined to try and return at some point late in the 2022-23 season.

"This has been a tough week for me as I have learned the extent of my injury," Gallinari wrote in a social media post. "This game means everything to me and not being able to be on the court with my Celtics teammates hurts. I plan to give everything I can to the Celtics organization and my teammates as we hunt for a title."

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The 34-year-old Gallinari was injured Saturday during a FIBA World Cup qualifying game against Georgia. He grabbed his left knee after a bounce pass in the lane before hobbling over to the sideline, holding the back of the knee as trainers rushed to his aid. Gallinari then limped to the locker room with the help of a staff member and a teammate.

The Italian team had announced that Gallinari suffered a torn meniscus.

Gallinari signed a two-year, $13.2 million contract -- including a player option for the second season -- with the Celtics as a free agent last month. The sharpshooting forward, who averaged 11.7 points and shot 38.1% from 3-point range across 66 games for the Hawks last season, was brought in -- alongside Malcolm Brogdon, whom Boston acquired in a trade with the Indiana Pacers in July -- to bolster the Celtics' depth and give them some additional offensive punch after the Eastern Conference champions saw their offense struggle at times in their NBA Finals loss to the Golden State Warriors. Gallinari has never played in the Finals over his 13 NBA seasons.

Long considered one of the NBA's elite-shooting big men, Gallinari is a career 38.2% 3-point shooter, and his 1,426 career 3-pointers ranks 23rd among active players and third -- behind Kevin Durant and Kevin Love -- among players 6-foot-10 or taller.

According to ESPN's Bobby Marks, the Celtics will be able to apply for a designated player exception to replace Gallinari. That will give the Celtics $3.2 million to either sign, trade for or claim a player on an expiring contract worth up to that amount.

Including Al Horford's nearly fully guaranteed deal, Boston has 11 guaranteed contracts on its roster along with several players with nonguaranteed or partially guaranteed deals expected to fight for roster spots in training camp.