As previously announced, Dragon Ball Z: Kakarot will have more playable characters than Son Goku.
At the Animation-Comic-Game Hong Kong 2019 currently underway, Bandai Namco unveiled for the first time gameplay with Piccolo (known as Satan in the Portuguese adaptation).
In addition to Piccolo, we know that Vegeta and Son Gohan will also be playable. Other characters like Krillin, Yamcha, Chiaotzu, and Tien will only appear as support during the fighting.
Dragon Ball Z: Kakarot is scheduled for early 2020. It gets gameplay (action starts from the 18th minute).