The Inter defender watched the first two matches of Andrea Stramaccioni's reign from the bench, but earned a penalty kick as a substitute in Wednesday's win over Siena
The 25-year-old entered the match in the 38th minute following an injury to defender Walter Samuel, with instructions from manager Andrea Stramaccioni to attack.
Down by one goal, the Nerazzurri pulled even before the half on Diego Milito's strike. The game continued deadlocked at one goal apiece until the 81st minute, when Nagatomo was pulled down by a defender while attempting to capture the ball on the far side of the goal. The referee immediately awarded a penalty kick, which Milito converted to give the hosts the 2-1 victory.
"I was able to get my body in there first," Nagatomo told reporters after the match. "I absolutely wanted to get the ball, and it's good that I was able to turn that into a result."
The appearance was the Japan international's first since Inter's 2-0 loss at Juventus, in which he received a caution in the first half. That match was the last for Claudio Ranieri, who was replaced by Stramaccioni in the following week.
"Even though it only feels like it's been a moment [since losing my starting role], I can't relax," Nagatomo said of the battle to regain his regular position. "In these conditions, I've reaffirmed that I absolutely have to work harder."