Friday night, the Rays manager felt he had to discipline Upton for a lack of hustle when he lifted his center fielder for not hustling on a double-play ball in the sixth inning. Maddon then announced Upton would not start Saturday night, and Saturday night said he was considering further discipline, though Maddon later said that Upton would start on Sunday.
Upton was also benched on Aug. 6 for lack of hustle during the Cleveland series.
"I'd like to believe that [it will not happen again], and he believes that also," Maddon said. "And I'd like to believe that it won't ever happen again."
Maddon, who delayed meeting with Upton because he was upset Friday night, met with Upton prior to Saturday night's game against the Rangers.
"He wasn't mad; it was more disappointed," said Upton, who showed contrition Friday night and continued to do so Saturday. "You don't want to disappoint the manager."
Maddon seemed to feel good after clearing the air.
"I'm not angry; it's more about disappointment," Maddon said. "You know what it's like when you have children and you say get the car home at a certain time or be home before a certain time and they don't. There's a certain amount of anger at first, but then a lot of it's based on disappointment. And that's primarily if I had to describe my emotions, it's that."
Maddon added that he liked Upton and called him a "wonderful young man."
"He's going to be a superstar in this league," Maddon said. "He's a big part of this organization in the future. But you have to draw the line at some point to make sure all the right things do occur in the years to come.
"He can be a catalyst for us during the playoffs. And I want him to understand that. But we have to work through some moments and issues right now to get to that point. And he listened very well, and I listened to him. And we're going to move it along. Last time is ancient history."
In baseball, not going all out to first base is acceptable in many cases due to the long season, but not to the degree Upton did Friday night when he covered the distance to first base in 5.33 seconds -- a distance covered by the average Major Leaguer in 4.3 seconds.
"There is a happy medium," said Upton, acknowledging his mistake.
Maddon said he is "just looking for continuous effort."
"Some of it has to be my perception of what's going on," Maddon said. "In every case it's on an individual basis, because some guys might have leg injuries, and I understand that. There may be some kind of a situation going on and that they're not going to be able to look the same, and I get that. But being that you're healthy, there's a certain way I want you to look and that's up to my eyes."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.