Inner quad Pain during the tail end of a ride and the next day (Soreness and pain)

Hi All,
Lately, I have been developing inner quad pain sometimes during the tail end of a ride and especially the next day. Fitness wise I feel good, but when I am go hard, I can feel the burn and pain while the HR is fine and under 150.
The pain is in the Vastus Medialis and Sartorius of the Quad muscle. I am enlosing a picture for those of you who are not aware of leg anatomy.
Could this be a fit issue? I was wondering if this is cause by my saddle being too close or too far from the handlebar? Any thoughts?

I ride roughly 6 hours a week mostly at Z2 to High Zone 4. Rarely Vo2Max. CTL around 40. TSB currently around -18 which is not out of the ordinary. 5-8inches at 172 lbs.


I should add that I eat around 1700 calories during non-cycling days and around 2200-2400 during cycling days as I am looking to get down to under 155 lbs. I am a Vegan but that is not relevant here as I have not had this Quad pain issue before.