The LA Galaxy announced on Sunday that midfielder Riqui Puig tore the anterior cruciate ligament (ACL) in his left knee during the Western Conference final against Seattle Sounders FC on Saturday night at Dignity Health Sports Park in Carson, California.

The player underwent testing on Sunday morning, and an MRI confirmed the diagnosis.

Puig will now miss the MLS Cup final on Dec. 7, when the LA Galaxy host the New York Red Bulls.

"Today begins a new challenge. I will be off the pitch for several months, but am already looking towards and motivated to return stronger than ever and ready to continue making history in this club," Puig wrote on social media on Sunday. "Thank you to everyone for your messages of support and love, they truly give me strength to tackle this recovery. I'm so proud of how hard we've fought to get here, and I know my teammates will give their all to bring the trophy home."

The midfielder sustained the injury during the second half of the match but continued playing for over 30 minutes in the 1-0 win over the Sounders despite the discomfort in his left knee.

Puig's even assisted the game-winning goal by Dejan Joveljic in the 85th minute of the match with a torn ACL, securing the team's place in the final. He is set to undergo surgery at a later date.

The former Barcelona player was an integral part of the Galaxy's success throughout the postseason, recording four goals and four assists in four matches. Prior to the playoffs, he managed 16 goals and 14 assists in 29 MLS matches to propel the Galaxy to second place on the Western Conference table with 64 points and a 19-8-7 (W-L-D) record.

The Galaxy's road to the MLS Cup final included wins over the Colorado Rapids in the first round, Minnesota United in the Western Conference semifinal and the Seattle Sounders in the conference final.

The team returns to the final for the first time since 2014, when the Galaxy triumphed 2-1 over the New England Revolution to win their sixth MLS Cup.