Jarrell Miller says he "messed up" after reported drug test failures forced an upcoming fight with Anthony Joshua to be scrapped.
Bradford have been relegated to Sky Bet League Two for the first time since 2013.
Lincoln missed the chance to be crowned Sky Bet League Two champions after their 19-game unbeaten run was halted by a 1-0 loss at play-off-chasing Carlisle.
Kyrie Irving had a hand in 11 of Boston's final 16 points on Friday night as the Celtics withstood a late charge by the Indiana Pacers to record a 104-96 win at Indianapolis and go up 3-0 in an Eastern Conference first-round playoff matchup.
Dillian Whyte's world title ambitions are at stake in a high-risk clash with the unbeaten Oscar Rivas at The O2 on July 20, live on Sky Sports Box office.