By Press Association A “concerned” Novak Djokovic is set to undergo medical tests after feeling the effects of being struck on the head by a bottle in his shock exit from the Italian Open. Djokovic was beaten 6-2 6-3 in just 67 minutes by Chile’s Alejandro Tabilo in Rome, the six-time champion committing 22 unforced errors, serving five double faults and failing to create a single break point. The one-sided loss came two days after Djokovic collapsed to the ground after being struck by a bottle which fell from a spectator’s backpack as the world number one signed autographs following his win o…