Sebek has been keeping up with training his body along with studying for school. There's no loss from inaction that Sebek aware of, so he thinks he can hold his own in these fights with or without the baton or his magic pen. He's stronger than a human after all.

He's heard of Vegeta's strength from multiple people, and yet, he's never had a chance to see it in action or test himself against it. Spotting him in the designated Fight Club area, Sebek yells confidently without hesitation, "Vegeta! Spar with me!"