It depends on whether Sinclair is given the all-clear for his blood clot in August. He can't play any contact sports til then as there's an increased risk of bleeding from the warfarin he takes. If he gets a recurrent episode, it could mean real problems to his career (may be on lifelong meds depending on his condition). As long as he is on anti-coagulants, he can't take to the pitch.
His is a rare case called upper extremity deep vein thrombosis UEDVT). The common ones are usually in the lower extremities (legs) called DVT or the lungs (Pulmonary Embolism, dangerous). I see what I can dig out about UEDVT.