It revealed more than soreness: Utley has patellar tendinitis in his right knee. The team has labeled the 32-year-old as "day-to-day," but there is no timetable for him to begin playing games. In fact, Utley will stop running and playing the field in any capacity until he feels better.
"We just don't want it to get any worse," Amaro said. "There's no reason for us to push him now and for it to be a problem in May, June, July, August. So we'll take it easy on him."
The Phillies expect Utley to be ready for opening day if inactivity for the knee relieves the pain.
"I hope it's just a minor blip," Utley said.
Utley, who has hidden his share of injuries and played through pain, was uncharacteristically compliant regarding the idea to slow things down.
"I try to look at things in the big picture," Utley said. "We have, hopefully, 200 more games to play this year. So I'd rather participate in the majority of them later on than early on."
The concern for this specific ailment is that Utley has experienced it before. This time, it hasn't gone away as quickly as Utley expected it to. So this may be best described as a "condition" and not an "injury."
"I've had it in the past," Utley said. "It comes and goes. Right now it's not going as fast as I wish it would. I think at this point it's better to be safe than sorry. I'd rather miss some games down here than miss some games during the season."
Utley acknowledged he may have to maintain and monitor the pain during the season, which could mean more frequent days off - something he has never taken kindly to. He indicated he's played through similar ailments before.
Amaro said the injury comes from "wear and tear," and that's what is most troubling. Utley is known for his intense work ethic when it comes to preparing his body for games. During those games, he beats his body up, typically losing at least 10 pounds during the 162-game schedule. He has three years remaining on a seven-year, $85 million deal signed in 2007.
The Phillies are hoping - with some gentle monitoring - to slow down Utley now rather than later.
"If he continues to aggravate it, it could get more painful," Amaro said. "We're just trying to cool it down. He's very aggressive. He doesn't like to take time off. This is a way to get him to take a little time off."
Beyond rest, there are other options for treatment. A cortisone injection could treat the inflammation. Players have used platelet-rich plasma therapy and shock-wave therapy to alleviate the pain. Surgery is also an alternative. A debridement procedure would remove inflamed scar tissue that can cause pain, but that would be a last-ditch option.
For now, the Phillies and Utley hope rest is the best cure. But given Utley's playing style, questions about his durability will persist until he returns to playing at a high level.
"He just has to be careful," Amaro said. "He likes to work so hard. I worry about all of our guys. Chase is going to just keep grinding it out, and that's the way it's going to be. This is just trying to slow him down."
Chase Utley played in only 114 games last season, sitting out after surgery to repair a torn ligament in his right thumb.
In 2007, he played in only 132 games after he suffered a broken right hand.
Utley played much of 2008 with a torn labrum in his right hip and underwent surgery to repair it after the World Series.
Contact staff writer Matt Gelb at firstname.lastname@example.org.
Follow him on Twitter at twitter.com/magelb