Once in a while, you here about a baseball player who injures their throwing arm, but they want to play so much that they learn to throw with the opposite arm. Billy Wagner comes to mind. Here is a story about a talented outfielder with the desire to play baseball, who switched to throwing right-handed following surgery on his left arm. Again, this is proof that throwing with both arms can be learned and is not a "gift" as some people might claim.
Staying On the Field
Cousino show strong desire to play
by Bubba Brown, 3 Nov 2010
After surgery to repair a posterior labrum tear, it didn't take long for Austin Cousino to start throwing again.
No, his left arm didn't make a miraculous recovery, enabling him to breeze through the extensive rehab. Ever the competitor, he was merely trying to get back on the field by learning how to throw righthanded, a feat he mastered.
"He decided he was going to do that after he was injured," said Tim Saunders, Cousino's coach at Dublin (Ohio) Coffman High. "It wasn't anything he practiced growing up. He decided he was going to play for us last year opposite-handed."