Barcelona has sent a letter to UEFA in protest at some of the referee's decisions in the 2-2 draw at Paris Saint-Germain in the Champions League quarterfinals. Club spokesman Toni Freixa said referee Wolfgang Stark of Germany 'did not apply the rules of the game.' Freixa specifically cited Stark's decisions not to stop play after Barcelona defenders Javier Mascherano and Jordi Alba collided and fell to the turf, and then forcing both off the pitch momentarily, leaving Barcelona to defend a corner with nine men, AP reported.