With MLB there is a high likelihood that weather will play a factor in the scheduling of games. This means MLB games are more likely to experience what is known as a "Rainout". When a "Rainout" occurs the affected game can either be delayed/postponed or rescheduled.
When games are rescheduled, often times, your tickets will be valid for the rescheduled date.
If you cannot attend the rescheduled date, you can resell your ticket on the SeatGeek Marketplace to try and recoup your funds. Follow this link for instructions on how to list your tickets for sale: Selling Tickets
If the venue is requiring an exchange of tickets in order to attend the rescheduled event please reach out to us at firstname.lastname@example.org and our Event Experts can assist you.