I had the same issue with the puppy class I took Delgado to. I started this thread to talk about it:
First Puppy Class - Issues
In the end there was no damage done to Delgado either physically or psychologically but I wouldn't recommend it. I'm no longer going to be doing a puppy class that allows play, I would rather them learn to focus on obedience in a class setting and just have a relaxed time then allow a free for all rough play. With the proper management puppy play time can be wonderful but it comes down to the trainer keeping control
Talk to the trainer, go early or stay late, or set up an appointment. Whatever works for you both and lay out your concerns, if you're happy with the rest of the class then you can skip the play time and simply go for the obedience/work phase.