For a number of years, Rashford has played on the left wing but is operating more centrally under the Dutch boss and, like Ronaldo, scored against FC Sheriff on Thursday.
That second-half substitute apperance for the England forward alongside Ronaldo could be replicated against West Ham on Sunday, according to Ten Hag.
“I think tonight with Cristiano and Marcus in the back worked well,” the manager told reporters.
“I was happy with that. To develop the team takes time. You can't go from zero to 100. You have to construct it from the outside, you need development before you go to the top, to the roof.
“Unfortunately, it takes time and I don't have time! I'm really the most impatient, but I have to, it's quite clear. Now, I think we're getting better defending with 11. Players are more and more aware of it, that we have to do it with 11.
“Also our build-up, I think we're improving game to game. Now, we need to do more to develop our attacking game but it's the most difficult part so it takes even more time.”
Ronaldo bounced back from being banished from the United squad to score in midweek, putting him on three goals for the season behind top-scorer Rashford on six.
“It's up to him,” said Ten Hag. “But I think when you collect all the chances he creates, the team creates for him in the last weeks, you see he's still capable to get in the right positions and he's still capable of finishing them.
“I think it's possible [he starts against West Ham], yeah. I know some see it [that way] I don't have a Europe team and I don't have a Premier League team. I look at the opponent and what we need, what suits the opponent.
“Now I have to focus on West Ham United for Sunday. We will pick the team to start but also have a plan B or plan C in our pocket to win that game.”