It is understandable to be concerned but you must keep in mind that these are not skills that your CP is not capable of, it's just some personal mental issue with completing it. There are many different reasons for blocks but the one consistant outcome is that that the child needs to decide in his/her brain that they want to try the skill again.
The
cupieqt approach is the most successful one that I know of and if a deadline like tryouts or a major competition is approaching than you can only remind them of it without pressuring too much. He/she may decide to end their cheer career, but more often than not I have seen it be a dramatic confidence booster when they learn they can overcome a major physical and mental obstacle on their own.
My other constant reminder to all parents and coaches is that this is the CPs issue, not yours.