Man Utd's Ten Hag determined to get the best out of a fitter Ronaldo
Ronaldo, United's top-scorer last season with 24 goals in all competitions, has been reduced to playing a part-time role this campaign, starting four times and netting twice.
Ten Hag said that the Portuguese, who missed pre-season and was linked with a move away, lacked sharpness early in the campaign but is now finding his feet.
"I want to support him as good as possible. We have certain demands from players, what we expect in certain positions," the Dutch coach told reporters ahead of United's home game against Cypriot minnows Omonia Nicosia in the Europe League on Thursday.
"I want to get the best out of him, he's in better shape now and I'm happy with that. At the start, it was the case (lack of fitness), it's proven once again, no one can miss a pre-season."
United are set to field a full-strength team against Omonia, who gave them a major scare before going down 3-2 last week, as they target top spot in Group E.
Ten Hag's second-placed side trail group leaders Real Sociedad by three points.
"We are going all out for the victory. It is Europe, it is tough... I told the players weeks ago, it was important to win the group. We want to win all the games, but it's clear, we want to avoid that (finishing second in group)," added Ten Hag.
Forward Anthony Martial (26), who only recently returned from injury but hobbled off again at Everton in the first half due to a hip problem, will miss out against Omonia.
"Of course, I want him in, sometimes it's disappointing when they aren't available because I know we need him. When they aren't, you have to deal with the situation," Ten Hag said of the Frenchman, who has three goals in his last three games.
Captain Harry Maguire (29) is also sidelined while midfielder Donny van de Beek (25) and right back Aaron Wan-Bissaka (24) remain long-term absentees.