The Page Rank effect of Academic recommendations for Graduate School
I’m worried if Letters of Recommendations not coming from the same ‘XYZ’ area Professor will not help my case.


While a letter from someone who is an expert in the subject of your doctoral research is better, it's much more important that the letter writer know about your research record.

Sensible graduate admissions committees know that not all universities have faculty in every research area.  They care more about what the letter says than who wrote it.