No, lah. He would not step down if his health is still good but weak. Although he may still wield considerable influence without being an MP, he is still game for a fight in his GRC come GE2016 unless his mental health is habis.
If he step down now and before the next GE a by election will have to carry out. So this become an issue for the constituency. And if he step down during the next GE, PM will just need to announce that in replacement with another new high calibre candidate.