Aston Villa have been ordered to make “sweeping and vigorous” changes to welfare protection for academy players after a Premier League inquiry found “evidence of bullying, aggressive behaviour and unacceptable language” by Kevin MacDonald, currently Villa’s under-23 coach.

The complaints against MacDonald by a youth player and his family who have asked not to be named led to a stern warning to the club, who were relegated to the Championship last season but were under the Premier League’s jurisdiction when some of the alleged offences were committed.

In 2012, Villa were granted Category One status under the League’s Elite Player Performance Plan. They have been placed on warning and details of MacDonald’s alleged conduct passed to the Football Association for consideration.

In the letter from the Premier League, seen by The Daily Telegraph, the father of a Villa academy player is told: “League officials are expected to have a regular presence in the club over the coming months to assess the club’s progress with implementing these actions. Failure to do so could have significant ramifications for the club.”