Among those who stepped in the batter's box against the two-time Cy Young winner were two hitters with credentials nearly as impressive: Michael Young and Chase Utley.
"He looked great. He looked like Roy Halladay," said Young, who played against Halladay for close to a decade when both were in the American League. "That was the Roy Halladay I remember seeing all those years in the American League. Everything was down in the zone; it had some zip; it was coming out of his hand really nice. I thought he looked great."
Utley, like Young, didn't take any swings against Halladay. Hitters often spend the first time in live BP tracking pitches.
Utley also used his keen batter's eye to give his own scouting report on Halladay.
"He looked good," Utley said. "He had a little life on his fastball - I know it's the first time - but it's always good to see a little extra life on the end of his fastball. It was good. It was crisp. He had a little giddy-up at the end. He threw some cutters, some changeups. Located them pretty well. I imagine he's pretty happy with how it went."
Halladay likely will throw in another live batting practice session before getting into a game for the first time within the next week.
"Doc was fine, Doc was fine," Dubee said when the first day of live batting practice was over. "Overall, I thought it was a good day of BP today. I thought most of the guys threw pretty well, as far as being in the strike zone, command, that stuff."
Dubee said he'll keep an eye on Halladay's mechanics and make sure the pitcher is repeating his delivery. He emphasized Halladay's legs.
"[Just making sure he's] keeping his leg strength, being able to carry his body fine and not losing his delivery with his legs giving out," Dubee said. "He's just like everybody, this is a building up process."
While many people found a spot along the chain-link fence at Robin Roberts Field to watch Halladay, the most impressive work might have come on the mound at Richie Ashburn Field.
After Cole Hamels got in his first live BP session of the spring, three relievers followed and showed off live arms in doing so. Jonathan Papelbon, Antonio Bastardo and Phillippe Aumont all made hitters wary of taking any cuts on a cool morning at the Carpenter Complex.
Jimmy Rollins shook his head hopelessly when Papelbon took a break from fastballs with a quick-moving slider. Although it was the first time each had faced hitters, Bastardo and Aumont were popping their respective catcher's mitts as if it were a midsummer game at Citizens Bank Park.
The 24-year-old Aumont might be the most intriguing pitcher in camp. He is 3 years removed from his first big-league camp. He's also coming off his first taste of the big leagues late last summer.
The experience and maturity could help him corral his talented arm and take hold of a permanent bullpen spot in 2013.
"Phillippe has a back-of-the-bullpen arm," Dubee said.
Aumont will have an interesting spring because he'll be doing some of his competing for a roster spot with the Phillies while wearing a different uniform. He is one of three Phils players, along with Pete Orr and Tyson Gillies, who will play for Team Canada in the World Baseball Classic next month.
"I think that exposure will be good for him," Dubee said. "We'll have eyes watching him, so we'll know what he's been doing."
Aumont, his fellow Canadians and Jimmy Rollins, who will play for Team USA, are expected to leave camp the first week of March.
Delmon Young continued to work on the side - playing catch - while the rest of the regulars took part in the third day of full-squad workouts. Young, who had microfracture surgery on his right ankle in November, will be brought along slowly this spring and is likely to begin the regular season on the disabled list . . . Cliff Lee and Mike Adams are among the pitchers scheduled to throw on Tuesday, the second day of live batting practice at the Carpenter Complex . . . Admission at Bright House Field is free for Friday's intrasquad game. The Grapefruit League season gets under way Saturday at 1 p.m. in Clearwater vs. the Houston Astros.
On Twitter: @ryanlawrence21