This would be a boolen setting in the gameplay settings menu. It would function in pet practice matches only, not in pet pvp matches. It would allow a player to decide if they wanted to cheer for their pets, or allow the computer to cheer for them the way it already does for the practice pet team.
reason: The computer is much faster than any player can ever hope to be and matches can be won or lost on just how fast someone can hit the cheer button. Also, factors such as network speed, age of player, and so on can affect if the player can ever hit the cheer button when it's green at all. This setting would allow a way to override problems in practice matches.
why not pvp too: you're matched against another player, not the computer. The same problems that affect you also affect, or can affect, them. No need to offset the computer's speed and infallability.