The German striker only entered the game in the final half-hour, as Barcelona won 2-1 on Thursday night.
Howe stated that he had to prioritize the player's well-being and fitness, saying, "I have to make decisions for the benefit of the player sometimes."
He added that he wanted to manage Woltemade's playing time to ensure he stays fit, particularly with teammate Anthony suspended for the next game and Jacob Murphy nursing an Achilles problem.
Despite the loss, Howe praised the team's effort, saying they were "really in the game" and had opportunities to score the first goal, which would have been crucial in the match.
The team's high-intensity play was evident, but they ultimately lacked the quality to secure a win, and Barcelona's Marcus Rashford scored two goals, with Anthony Gordon's late goal coming too late to change the outcome.