Leipzig - RB Leipzig forward is set for a lengthy spell on the sidelines after tearing ligaments in his right knee during Sunday's 1-0 home defeat to Bundesliga 2 leaders FC Ingolstadt 04.

The news comes as a bitter blow for the 23-year-old USA international, who only made his first-team debut as recently as 17 October, having suffered a partially torn anterior cruciate ligament in the same knee in a pre-season friendly against English Premier League side Queens Park Rangers in July.

Boyd has scored two goals in seven league appearances since joining promoted Leipzig from Austrian club Rapid Wien in the summer.