Red Bull Leipzig says American forward Terrence Boyd has torn a ligament in his right knee, just two months after returning from a similar injury.

Boyd was injured in the first half of Sunday's 1-0 loss to Ingolstadt in the German second division, and Leipzig announced on Twitter that the American had torn his anterior cruciate ligament and lateral meniscus.

Boyd already missed the start of the season because of a partially torn ACL.

Boyd was born in Bremen, Germany, but has made 13 appearances for the United States national team since 2012. He was not included on the final World Cup roster this year.