Background: The study was aimed to evaluate whether a mechanical biaxial tester can be used in a uniaxial mode to evaluate the mechanical properties of tendons. Materials and methods: The study was carried out on specimens of porcine superficial digital flexor tendon (n = 9). The mechanical properties (elastic modulus, and stress at 15% strain) were measured two times consecutively in the uniaxial mode with the BioTester® 5000 (CellScale) equipment. Results: Values of 0.313 ± 0.096 MPa for the elastic (Young’s) modulus and of 0.702 ± 0.174 MPa for the stress (at 15% strain) were measured, indicating that the porcine superficial digital flexor tendon is not a strong tendon. Conclusions: When suitable specimens cannot be obtained for a biaxial evaluation, tendons can be evaluated mechanically in the BioTester® 5000 employing the uniaxial mode.