Kenan Yildiz and Weston McKennie put Juve 2-0 up at the break and Vlahovic set up Nico Gonzalez for the third but failed to find the net himself on Juve's return to Europe's elite club competition following a one-year absence.
Vlahovic was visibly upset when he missed two chances towards the end of the game as he remained goalless in a third consecutive game across all competitions.
"Dusan always shows up in ideal conditions to train and play. I am happy with his work," Motta told Sky Sport.
"Today he didn't score and it's true that the striker always wants to score, it is also right that he has this ambition. (But) he must manage the emotional side.
"It happens to a striker not to score but he must think that on the pitch there are other things to do and that the goal will come. We also have other strikers, the important thing is that he participates in the team game."
Motta, who was appointed in June after the club parted ways with Massimiliano Allegri, was pleased with the win but believes his team can get better after his debut as a coach in Europe.
"Today I liked the concreteness," he said. "(But) we can improve in many other things to make things difficult for our opponents.
"The goal we conceded is the thing that worries me the least.
"We can do better in terms of quality. We are going on the right path. We started the competition well with a win and now we shall continue like this".
Juve, who remain unbeaten in all competitions so far this season, next face Napoli and Genoa in Serie A before they travel to RB Leipzig in the Champions League on October 2nd.
