With that neckproblem now understood to be fully healed, Schumacher is thought to be close to completing a sensational return to the sport with German giants Mercedes.
The Lions were already two casualties down by then, tight-head Murray departing with an ankle injury after just seven minutes and Hook following five minutes later after a lengthy period of treatment for a neckproblem.
The Ospreys' back-row resources will be stretched with Andy Lloyd likely to miss the Munster tie with a neck injury, although Ryan Jones should be back after a rib problem.