I am not from the US and my field is in the social sciences. A while back, I started collaborating with a foreign professor on a research project which is now under review and another one which is halfway through. however, I did not find these topics very fulfilling and I want to move to another area closer to my original interests (I already have two other published papers relevant to this new area). The complicating issue is that the professor has told me several times he would be very interested in having me as a PhD student. So, I guess, he may not appreciate the fact that I have decided to pursue another area with another supervisor. Therefore, it may not be very fair or wise to ask him for letters of recommendation. What worries me, however, is that if I list these papers in my CV (which I eventually have to when they get published), it may raise questions/suspicions about why I have not asked him to recommend me. I cannot preemptively tell my prospective supervisor or the admissions committee the real reason for my reluctance to ask this professor. So, I am concerned that if such questions arise in their minds, it may lead them to mistakenly assume that I have something to hide, motivating me to exclude this professor as a potential recommender.
Is this a legitimate concern?