As long as you have an institutional official who can attest to your salary and > 1/2 time research status for at least 2 years, there is no administrative hurdle. However, if I was reviewing your application and I would ask myself the question "How would this help this candidate maintain a research career?" I wouldn't see it as necessary for a resident who is not missing out on any clinical earning potential and could very easily drop research after residency vs. a fellow in a research intensive fellowship who is missing out on clinical earning opportunities in order to do research. Remember that this is not a grant that is awarded based on the awesomeness of your research, but rather a way to incentivize early career researchers to choose research over more lucrative clinical work.