Bale is expected to be the main source of goals for Madrid this term, and the attacker has netted in each of the Spanish outfit's last three pre-season fixtures.
The 29-year-old managed 21 goals in all competitions for Los Blancos last term, and Lopetegui has said that the Spanish club "are so happy" with the former Tottenham Hotspur left-back.
"I'm not going to talk about past seasons. The Bale we have now is committed, content, wanting to have a great season. He is training very well, happy, and we are so happy with him. This has only just begun," Lopetegui told reporters.
Bale - linked with a move to Manchester United earlier this summer - has managed 88 goals for Madrid since arriving at the club from Tottenham Hotspur in 2013.