Can I be laid off while off on worker's compensation?

Yes, if you would have been laid off even if you were not on worker's comp.  In other words, your employer can not lay you off because you were on workers' compensation leave, that might be illegal retaliation. But, if your employer would have laid you off even if you were still on the job, the fact that you are on workers' comp leave doesn't protect you from layoffs. Good luck.