This study investigates the construction quality and potential defects of grouted sleeve connections in a prefabricated bridge pier dismantled from a project in Shanghai using section-cutting inspection. Ten samples were examined with a focus on grout compactness, reinforcement anchorage length, and centering accuracy. The results show that the grout within the sleeves was highly compact, and all mechanical performance indices satisfied the relevant specifications and design requirements, indicating overall reliable construction quality. Minor deficiencies, including slightly insufficient anchorage length and deviations in reinforcement centering, were identified but are considered to have negligible effects on load-bearing and deformation capacities on the basis of existing research. The findings suggest that the current construction process generally meets quality requirements; however, improvements in grout mix proportion, construction procedures, and the addition of external threading on the sleeve surface are recommended to enhance bonding with surrounding concrete. This work provides experimental evidence from an actual engineering case to support the safety and durability assessment of grouted sleeve–connected piers and supplements nondestructive testing by revealing internal defects that are otherwise difficult to detect.