The England defender helped United to a 1-0 win at Wolves on New Year's Eve and could start in the middle again against Bournemouth on Tuesday.
Lisandro Martinez has resumed training and may be available but, should the Argentina World Cup winner fail to make it, Ten Hag has no hesitation about calling on Shaw again.
"You have a plan, sometimes it changes by circumstances like illnesses. Casemiro did well at centre-half, like Shaw against Forest," Ten Hag said.
"The way we were to approach Wolves, I thought it was the best match with Rafa (Varane) and Luke, you know the speed of Wolves over the right side and he could cover that.
"We wanted to attack on the left side with an offensive game from Tyrell Malacia and, in possession with a left footer, you get better angles on the pitch.
"He was impressing but he is also good as a left full-back. It's an extra option which is always good."
Ten Hag was unhappy with United's first-half performance at Molineux before Marcus Rashford came off the bench to score the winner, which moved them into the Premier League's top four.
Rashford had been axed for oversleeping and being late to a team meeting.
Ten Hag felt there was a lack of focus from his side in the first half but believes they quickly rediscovered their drive.
"I saw a different approach in the second half, there was more investment, more focus, aggression. We had a better organisation in the second half and created more chances," he said.
Diogo Dalot is making progress from his hamstring strain while Scott McTominay (illness) should return to the squad.