The Manchester United striker added another two goals as the Red Devils booked a place in the Carabao Cup semi-finals with a 3-0 victory against Charlton.
Rashford has scored in all six games since the domestic campaign resumed last month and Ten Hag is confident that the player will add to his tally.
The coach said: "I have told you many times, when he brings himself into position, when the teams puts him in the positions, in the one-on-ones in the box he will score and that is what he is doing at this moment.
"So if he keeps the focus and keeps putting the effort in he will keep on scoring.
"What you see now with Rashy, that is quite obvious, it wasn’t at the start of the season but now he is in the right moment."
Rashford's late goals were required after United failed to kill off the lower-league side and Ten Hag challenged his players to be more lethal at the top end of the pitch.
He said: "The first half-hour I was quite happy, I was less happy with being clinical in front of goal, we need to be more effective there because we created good chances in the first half-hour.
"We should have scored more in the first half and also second half there was a good save and a few moments where we needed an extra pass but we didn’t so until the end we had to fight for it.
"I don’t think they created really good open chances but still you never know. We are progressing after the winter break, this is the third time we have won 3-0 which is good but we have to be more clinical.
"But we have scoring players in our team."