Hard Bat or Sponge Bat

I play in a local league. I used to play hard bat and was able to beat some better opponents using it since they are not used to the reaction of hard bat.

Since I have move to sponge bat my better opponents are beating me.

My question is can I change my bat to my old hard bat during the games with a better player and change back to my sponge bat for the rest of the match?

Stan