Clarets midfielder Ashley Westwood suffered a serious ankle injury whilst challenging for the ball with West Ham's Nikola Vlasic who was visibly upset after the Clarets player had gone to ground.
Westwood immediately signalled for help and was quickly consoled by his concerned Clarets team mates.
After a lengthy stoppage, Westwood was stretchered off to applause from both sets of players as part of a half in which Burnley led 1-0 at the interval.
The contest is Burnley's first game since the club decided to sack boss Sean Dyche after ten years in charge.
Mike Jackson, the club's under-23s boss, is in temporary charge, assisted by Academy director Paul Jenkins, under-23s goalkeeping coach Connor King and club captain Ben Mee.
Wout Weghorst's header put the Clarets 1-0 up at West Ham and the Clarets then squandered a chance to double their lead at the end of the half when Maxwell Cornet missed a penalty.