Dudley Heathens have added Adam Portwood and Brendan Johnson to their team to replace Danny Stoneman and the injured Richard Franklin.
Franklin may require surgery on a torn ligament in his knee and faces at least a month on the sidelines.
Stoneman has been released to make way for 16-year old Portwood.
"We wish Danny all the very best and hope he gets fixed up elsewhere as soon as possible," said Heathens team boss Will Pottinger.
"The management decided to cast an eye towards the future with Adam Portwood, and we have to start looking at working with our own riders rather than trying to find riders from elsewhere."
However, the Heathens have turned to former Isle of Wight rider Johnson in the temporary absence of Franklin.
"Richard's injury is a blow, he also has a cyst at the top of his knee and he was hoping to put off the operation until the end of the season," said Pottinger.
"We have been very fortunate to have Brendan on board so quickly, we were thinking about him in the winter and he is a former British Under-18 champion."
Johnson and Portwood will make their Heathens debuts at the Isle of Wight next Tuesday.