Connor Mountain had to be taken to hospital after falling alongside team-mate Rik Mullins, bringing MK Knights’ match with Kings Lynn to a premature end last Wednesday.
Mountain and Mullins crashed in Heat 4 with Knights 12-11 up.
The teenager was taken to hospital with considerable tissue damage and the race was called to an early end.
Fortunately, Knights’ follow-up race against Long Eaton was a much calmer affair, though Knights came away from it with a defeat.
In a much changed Knights team only Sam Chapman and Niall Strudwick were able to mount a serious challeng against a rejuvented Long Eaton side.
These results see the MK Knights retain their position, 10 points clear, at the top of the MIdland Development League table.