Okay first point you say CK gets hurt which means:
1. He couldn't have his powers due to kryptonite for him to be able to be injuried or another meteor giving him a concussion.
2. For his injury to last very long the kryptonite exposure would have to be on going for his powers not to return in a couple of days and for him to then heal quickly.
Second point - M & J. If you want them not to be able to go to Clark you can have several things going on:
1. CK wouldn't contact them because he is wallowing particularly if they thought he shouldn't do what lead to the exposure to kryptonite.
2. Have M & J in a very far off country that takes like 2 days to fly back by plane - Australia as an example.
3. Have M or J injuried while on vacation with some type of injury that would be likely for what they were doing - broken bones, severe strains or illness and doctor won't let the sick or injuried person travel. You would have to check with someone with medical knowledge about what sorts of things a doctor would forbide air travel. Like a severe inner ear infection.
