The England international lasted close to 90 minutes for the Citizens in their 2-0 win away to Arsenal on Sunday, despite only returning to training at the start of the week following his World Cup exploits.
Speaking after the match, the 23-year-old revealed that he could not wait to get back involved following a three-week rest.
"I couldn't wait for my holidays to finish. I needed to get back and I'm really happy I could be involved today," he told BBC Sport. "I wanted to play and it's great that we got three points.
"We did the job we needed to do. There were some scary patches but it's a great start to come here and get three points.
"It's about having a winning mentality that the manager is trying to instil in us. We have to keep doing these things. We can't just be happy with the Premier League last season. That's gone now - we need new challenges."
Sterling has now scored 50 Premier League goals, with his opener against Arsenal only his third from outside the box.