The Rhino in Right Field by Stacy DeKeyser

But the contest is on a Saturday--the day Nick has to work in his fathers shop. There's one other tiny--well, not so tiny--problem. A 2,000-pound rhinoceros named Tank. Nick and his friends play ball in the city zoo--and Tank lives just beyond the right field fence. Nicks experience getting the ball out of Tanks pen has left him frozen with fear whenever a fly ball comes his way. How's a lousy fielder going to win the contest?

Nick practices every day with his best friend, Ace, and a new girl who has an impressive throwing arm! But that's not enough--to get to the contest, Nick has to lie to his parents and blackmail his uncle. All while dodging the school bully, whos determined to win even by playing dirty. Nick will need to keep his eye on the ball in this fast, funny story about a game that can throw you some curveballs--just like life!