"The biggest concern is that we just watch him play and they don't bring their egos into the game and do what they've been doing," D'Antoni said Sunday.
The Lakers went a commendable 10-9 without Bryant, who returns Sunday night against Toronto after missing almost eight months because of a torn Achilles' tendon.
"We have to take a step forward. We can't take a step backwards," D'Antoni said. "Hopefully that's the case."
Bryant will play 20-something minutes in his first game since April 12, D'Antoni said.
"In the heat of the battle, we'll find out," D'Antoni said. "I don't think anybody knows how he's going to react to the first three or four minutes. He might need a quick blow or he could go a little bit longer."
Bryant did not talk to reporters after Sunday's shoot-around. He has gone through more than six practices but the speed of a game will be "completely different," D'Antoni said.
"That's why nobody really knows," D'Antoni said before mentioning long-time Lakers trainer Gary Vitti. "We have kind of a loose plan. As the game goes on, Gary and I will be talking the whole time, doctors are right there at the bench and they'll be talking. Kobe will be the ultimate decider in how he feels."
The Lakers have won 10 consecutive games at Staples Center against Toronto, their last home loss to the Raptors coming in December 2001.