Amaro described Howard's condition as seroma - a pocket of clear fluid that sometimes develops in an area after surgery. Manuel told two reporters Saturday that an infection was "a little setback" to Howard's recovery. Amaro later clarified his manager's comments.
Sheridan said it is a common occurrence, especially after Achilles tendon surgery.
"The Achilles tendon is notorious for not healing well - the skin over top of it," Sheridan said. "Sometimes these things happen, and that's why when you look at setting time frames, you never say somebody is behind or ahead of schedule until they are on the field."
Sheridan reinforced Amaro's message, saying this was not a setback for Howard, although he will miss at least a few days of workouts.
"We wanted Ryan to go back and see Mark, so this is kind of a scheduled appointment," he said. "He just has a nice little adjunct to it that he is going to have something else to look at. We think it's important that Mark kind of helps us make these decisions in where he progresses. He did not have a setback, and that's why we're sending him there. It's just something that happens as part of the rehab process."
Sheridan said he has been pleased with Howard's rehabilitation to date.
"Ryan has been doing great," Sheridan said. "He has been out on the field and has been doing the things we expected him to be doing at this point. Hopefully, we can keep it going in the right direction."
Howard has participated in full batting practice, but Sheridan said the biggest challenge lies ahead.
"Running and cutting," Sheridan said. "Basically reenacting how it happened. Coming out of the box and making that first push, stopping, starting, and turning is the challenge. Running straight ahead is easy. You start to add those other things and it becomes more difficult."
Cliff Lee, sidelined by what the team has termed mild abdominal soreness, threw a bullpen session Sunday morning without any apparent problems.
Both Lee and the team downplayed the injury, which caused the lefthander to skip his last scheduled bullpen session. Lee has a history of abdominal problems, especially during the spring. He missed most of spring training and didn't make his first start in 2010, being out until April 30, because of an abdominal strain.
"Cliff looked fine," pitching coach Rich Dubee said.
Lee will return to his normal schedule and throw live batting practice Tuesday.
On the first day of live batting practice, when Phillies pitchers throw to their hitters, Dubee singled out Jake Diekman, Phillippe Aumont, and Kyle Kendrick as pitchers who impressed him. . . . New outfielder Laynce Nix arranged a trade for Michael Martinez's No. 19. Martinez will wear No. 7, previously assigned to Nix.
Contact staff writer Matt Gelb at firstname.lastname@example.org or @magelb on Twitter.