The 23-year-old right fielder does have five years of big league experience, but D-backs manager Kirk Gibson knows Upton has grown up because he's seen it.
"He's just more polished," Gibson said. "He understands his role much better and he's not trying to live up to what everybody else thinks he should be."
On Thursday, Upton hit a walk-off home run in the 10th inning to propel the D-backs to a much-needed 3-2 victory over the Giants.
Gibson said that earlier this season, in Houston, he talked with Upton to reaffirm that he didn't care if he was a superstar.
"I just want him to be a championship player," Gibson said.
Upton said the difference between the two is simple: winning.
"For me, everybody that's on a winning team is a championship player," he said. "They did something to contribute to that."
Upton entered Friday's contest against the White Sox hitting .291 with 12 home runs and 35 RBIs, but he understands he not a finished product.
"I wouldn't call myself a complete hitter yet," Upton said. "But I think it's about not worrying what I'm doing; It's worrying about what can I do to make the team better?"He then went 3-for-3 with a walk, RBI and a run scored in Friday's 4-1 victory to raise his average to .299 and give him five straigth multihit games