I’ve seen people rig up roller bearings to engrave water bottles, so the bottle rotates instead of moving. That gives them one dimension to engrave in. There are several examples in the forums, like Laser engraving on cylinder e.g.water bottle
That said, your tennis ball is fuzzy and spherical. I don’t know how well the sphere would handle the rotation without twisting in a different axis. You might need some kind of jig to prevent that, while still allowing rotation. I don’t think the laser would interact well with the fuzzy surface either. You might need to shave the tennis ball first. Otherwise, I don’t see why it wouldn’t work.