Mineralized collagen fibrils are a crucial subunit in native bone, with load bearing and biological properties which influence the health and functionality of all bone hierarchical structures. In the realm of bone disease or injury, there is large focus on a 3D matrix which can function as a viable bone graft for patients with large bone defects. Type I collagen and hydroxyapatite have been highly desirable materials to use for these bone implants due to their prevalence and structural role in native bone. However, creating a mineralized collagen matrix which mimics in vivo mineralized collagen structures and arrays in bone has been an arduous task for many researchers. The novel PILP method of collagen mineralization has shown promise in creating a similar mineralized collagen profile in vitro as seen in native bone and has already been studied extensively when mineralizing larger collagen constructs. This study aimed to look more closely at the effect of strain on the mineralization of individual collagen fibrils, and to better understand how the presence of strain impacts the fibrils’ mechanical properties and Young’s modulus. A glass microneedle micromanipulation system mounted on a DIC microscope was used to mineralize and mechanically test individual rat tail type I collagen fibrils. The results of the study showed a wide range of Young’s Modulus and yield stress values within each experimental group, with overall Young’s modulus values ranging from 0.03 to 0.4 GPa and yield stress values ranging from 8 to 40 MPa. There was no statistical difference between the experimental groups, and the data was too noisy to draw any solid conclusions about the effect of strain and mineralization on the mechanical properties of collagen fibrils. However, the glass needle micromanipulation method for mineralizing and mechanically testing the collagen fibrils is robust and has powerful applications in other areas of nano-Newton level mechanical studies.