Clement Lenglet says patience must be shown with Ansu Fati after the 16-year-old's brilliant display against Valencia.
Ansu, still 16, made his first start for Barcelona against Los Che and scored and assisted in the first seven minutes of the game.
The teenager came close to scoring again and had a penalty appeal turned down before being replaced by Luis Suarez to a standing ovation.
"He's 16 and we have to be patient with him," Lenglet said. "It's true he's taking advantage of the chances he's getting and he's a good kid who deserves what's coming his way.
"I am really happy for him, but we must give him time because he's 16 and things can quickly change. I hope not, but we have to take care of him and support him when he plays.
"My advice would be to listen to people and work hard because it's very difficult to play for Barcelona."
Barça won 5-2 in the end but the two goals conceded will raise questions -- that's seven conceded in four league games this season.
"We prefer not to concede goals but we did well until the end," Lenglet said. "Overall, we played really and despite conceding what's important was the response.
"It's a good win against a tough rival who play good football. They play differently to us but we did things really well.