The Portugal forward has been linked with a move to a Champions League club before Thursday's transfer deadline and was again left out of Ten Hag's starting line-up for Saturday's 1-0 win over Southampton.
Ronaldo came on after Bruno Fernandes had given the visitors the lead and at full-time stopped to salute the raucous Manchester United fans, leaving some to speculate he was saying goodbye.
But Ten Hag said: "We played with him. So we want him to stay. That is what we want. I hope so."
Ten Hag reiterated his position when asked if he would be satisfied should United not add to their forwards this week, adding: "We have Cristiano Ronaldo, we have Anthony Martial, we have Marcus Rashford, so then we are OK."
Ronaldo, who came on for Jadon Sancho, was one of three substitutes Ten Hag made at St Mary's, also swapping Anthony Elanga for new signing Casemiro in the 80th minute and Fred for Christian Eriksen in second-half stoppage time.
Casemiro completed his transfer from Real Madrid on Monday and his new boss was pleased to get him involved.
"I think it was quite good for him to see what the Premier League is (like), its different style," Ten Hag said.
"He has played some games, he played one time 90 minutes, but he is fit, he had a good pre-season with a lot of training sessions and now we have to integrate him in a team, in a way of play, and integrate him with his team-mates."
Victory was a second in a row for United, who had started the Ten Hag era by losing their first two Premier League games.