The 37-year-old has told the Red Devils that he wants to leave this summer, as he is determined to continue playing Champions League football at this stage of his career.
However, the clubs thought to be in the running for his signature - Chelsea, Bayern Munich and Paris Saint-Germain - have all allegedly decided against signing him in the current market.
Ronaldo did not travel with the Man United squad on their pre-season tour of Thailand and Australia due to a personal issue, which has remained private.
Atletico Madrid are the latest club to be strongly linked with the Portugal international, but Ten Hag is planning for the 2022-23 campaign with the experienced striker in his squad and has also claimed that he could stay at the club until June 2024.
"I am well informed he also has also an option (to extend his contract), eh? Yes (he could stay beyond this season), but to be honest, of course I have signed here for three years, but in football it's short-term as well. We have to win from the start. So I don't look that far ahead," the Manchester Evening News quotes Ten Hag as saying.
"I have a strategy, it's a process, it takes time, but in the end we have to make sure from the outset there is a winning team."
Ten Hag, though, has admitted that he is unsure when Ronaldo will report back to the club's Carrington training complex, claiming that there is "no change" to the situation.
"The same status as last week in Bangkok: no change. I cannot tell you (when he will be back at Carrington). No change in the issue. He is training. I think we all know Ronaldo is a top professional and he will be fit. That is the last concern I have," he added.
"In his career, he has shown everything. I have set my demand. We want to play in a certain way. A top player can contribute and Ronaldo is an absolute top player in our squad. The players dictate the way you play. Especially players who score goals because they are extremely important for a team. You construct your team around them."
Ronaldo, who has denied that he is in talks over a return to Sporting Lisbon, scored 24 goals and registered three assists in 37 appearances at club level last season.
Speaking earlier this month, Ten Hag reiterated that the Portuguese was not for sale, with the player's agent Jorge Mendes seemingly thus far being unsuccessful in his attempts to find his client a new club.
"We are planning for Cristiano Ronaldo for the season and that's it," Ten Hag told reporters. "I'm looking forward to working with him. I have read [that he wants to leave], but what I say is Cristiano is not for sale, he is in our plans and we want success together.
"I spoke with him before this issue came up, I had a conversation with him and I had a good talk. That is between Cristiano and me. What I can confirm is we had a really good conversation together."
Man United have four more friendlies this summer against Crystal Palace, Aston Villa, Atletico Madrid and Rayo Vallecano before their Premier League opener against Brighton & Hove Albion on August 7.