Usually, clotting blood cells called thrombocytes or platelets, because of the shape they have, are responsible for the coagulation process. Thrombocytes help in the coagulation process, creating clots that stop the bleeding. They release thrombokinase which react with prothrombin when calcium is present, finally forming thrombin. Fibrin, which creates the clot structure, is the result of fibrinogen conversion. This conversion process is achieved due to the presence of thrombin.
On the other hand, lymph has a composition that can be compared to blood plasma, a composition that contains white blood cells but not thrombocytes, which are responsible for the clotting process. That said, there are studies that confirm the presence of other clotting factors in lymph composition.