Act 1, scene 2 contains no references to baseball. Are you sure you mean this scene? Troy never actually plays baseball anywhere in the play. We discover that he learned how to play baseball when he was in prison (Act 1, scene 4) where he served 15 years. He was good enough to play in the Negro leagues, but by the time he was released from prison, he was too old to play in the major leagues, Pearl tells us in Act 1, scene 3. As a result Troy not only feels bitter about missing his chance, but he also fears that sports will somehow trick or disappoint Cory. Therefore, he insists that Cory quit the football team and give up his plan to go to college; instead, Cory must pursue a steady job like working at the supermarket. In addition, Troy fears that Cory may be a better athlete than he ever was.
Baseball becomes a metaphor in the play for Troy's hopes and disappointments.