"Any time one of our starters has to get an MRI," Amaro said, "it's alarming."
Although Lee was placed on the 15-day disabled list before the end of the night, the results from the MRI that came down after the game were at least somewhat encouraging.
Lee isn't headed for surgery; he's in line for a few weeks of rest.
He was diagnosed with a grade 1/2 left elbow strain.
"It's never good news whenever you lose one of your No. 1 pitchers, but it's pretty mild," Amaro said. "But it's a strain and we want to be careful with him."
Since Lee will be shut down from throwing for at least the next week, he isn't likely to return when the DL stint expires. The Phillies hope he'll return within the next month.
"Hopefully it was caught early enough with the mildness that it is," manager Ryne Sandberg said. "He's had good outings right up to it. It just came on the day-after effects. So hopefully it's mild enough that we'll have him , get it behind us, taken care of."
Lee said he first felt discomfort last month, in his fourth start of the season on April 16 against Atlanta. He threw a career-high 128 pitches in a 1-0 complete-game loss that night.
But it was mild enough that Lee was able to pitch through it while using anti-inflammatories to combat the pain. At least up until his start on Sunday against Cincinnati.
"We started doing treatment on it, and it was acting like it was getting better," Lee said of the last month. "Then this last start I started to feel it the last couple of innings, just about every throw. Obviously it was pretty sore the next day and I felt it trying to play catch . It was there on every throw.."
Lee is 4-4 with a 3.18 ERA in 10 starts this season, his fourth since signing a 5-year, $120 million free-agent deal with the Phillies in December 2010. He earned his fourth win of the season on Sunday, when he held Cincinnati to two runs on nine hits in 6 2/3 innings.
His current bout with elbow trouble is unchartered territory for Lee, who turns 36 in August.
"I really don't know ," Lee said. "This is new to me. I've never had anything like this. They seem to think that not throwing for a week it should be quite a bit better. I don't know if it'll be gone, but you don't really know until you get there. Hopefully in a week it's gone, then play catch and in another week I'll be back in games."
But Lee was at least thankful the MRI results didn't mean his 2014 season was in danger.
"I was hoping it would be minor," Lee said. "I don't know if this is minor, but it's definitely not a ligament. So the Tommy John thing is not what it is. So that's good. But we knew it wasn't that from the tests they did on me. They assumed it was the flexor tendon, but you don't really know until you get an MRI and confirm it."
A.J. Burnett, who earned his 150th career win last night, was among many in the Phillies clubhouse relieved with Lee's MRI results.
"It's better news than the other, so you're happy for that," Burnett said. "We'll hold the fort down until we get Cliff back. I said my prayers last night, I'm sure some other people did too. It wasn't great news, but it was better than the alternative."
Revere sits again
For the fourth straight game, Opening Day centerfielder Ben Revere was not in the starting lineup. Tony Gwynn Jr. started in his place.
Ryne Sandberg said Revere is healthy after a stomach virus, but shied away from questions about whether Revere had lost his everyday job.
"There's some different options there," said Sandberg, who has used both Gwynn and John Mayberry Jr. in center in the last four games. "It's also an opportunity to try some different things."
Sandberg said, like his lineup, centerfield remains a fluid, "day-to-day thing." Cesar Hernandez, however, doesn't appear to be an option for centerfield, despite playing 22 games at the position at the end of the 2013 season.
"With him being so good at second base the way that he is, it was an organizational decision to keep him on the dirt, with him going forward to play the other side of the diamond," Sandberg said. "Everyone thought his infield skills would kick in at third base and at shortstop.''
Righthander Jonathan Pettibone, on the disabled list at Triple A with a shoulder injury, is expected to be examined by Dr. James Andrews today . . . Darin Ruf went 2-for-3 with two doubles and a walk yesterday for Triple A Lehigh Valley. He homered on Sunday. Ruf missed the first 7 weeks of the season after suffering an oblique strain a week before the Phillies broke camp in spring training . . . Jimmy Rollins' leadoff home run on Sunday was the 46th of his career, fourth in major league history behind Ricky Henderson (81), Alfonso Soriano (54) and Craig Biggio (53).