Soccer Scoop: Who's making a fool of Mac? (Matt Christopher Sports Classics)

Mac Williams, goalie for the Cougars, is known as much for his upbeat game chatter as for his outstanding saves. But when an anonymous artist starts making fun of him with a weekly cartoon, Mac is anything but upbeat. To make matters worse, he suspects that somebody close to him is the cartoonist. Would one of his friends really betray him-or is there someone else who wants to make him look ridiculous?