Halladay is one of five such instructors the Phillies are employing this spring; Brad Lidge, Larry Andersen, Gary Matthews and Dave Hollins also will be working with the team at some point in camp.
Since he is working with the pitchers, including some of the younger and more raw ones in camp, Halladay was already at work when camp opened for pitchers and catchers last week. He has drawn rave reviews.
"Are you [kidding] me?" pitching coach Bob McClure joked of Halladay's usefulness. "Doc is such a levelheaded person, so he's easy to talk to about things like that. If he's critical, it's in a helping way and not a bashing way. It's more like he's being critical to help the guy. It's not, 'He can't do this.' It's, 'He's having trouble doing this, and this is how he can do it.' It's been outstanding."
Halladay, who is working with the Phillies for a few weeks this month, sits in on meetings with the pitchers and coaching staff each morning. He has sat in with McClure during talks with individual pitchers, too.
On a recent day in camp, Halladay watched Cuban free agent Miguel Alfredo Gonzalez from behind a cage, chatted up former teammates Jonathan Papelbon and Cliff Lee during a postworkout lunch in the clubhouse, and then sat next to top pitching prospect Jesse Biddle in the back corner of the same clubhouse and discussed pitching with the 22-year-old lefthander, one-on-one, for more than 20 minutes.
Halladay said he has tried to incorporate a little bit of everything into his chats with pitchers, not focusing only on a mental approach or routine and preparation. But he did use the word "brainwashing" in explaining his attempts to get some pitchers on the right path.
"Anything they want to talk about," Halladay said. "We've talked mechanics, mental stuff, pitch selection. We've really kind of covered the gambit. I enjoy talking pitching and talking baseball. And I don't have all the answers. I don't claim to, but I'm more than happy to share my beliefs.
"I don't think there's going to be one sit-down with everybody, but just getting those chances - 5 to 10 minutes here, 5 to 10 minutes there, maybe walking out to the field - hopefully you say something, you spit out enough stuff that maybe there's something that sticks. All of them have been very good, very receptive and willing to learn."
Halladay first joined the Phillies in 2010 after 12 seasons in Toronto, where he won the first of his two Cy Young Awards and made six All-Star teams. But success didn't come immediately for the former first-round draft pick, who famously had to be sent all the way back to Class A after making it to the big leagues and flirting with a no-hitter in his second major league start.
Halladay has plenty of life experiences that he can share with players in camp, in addition to pitching advice. So far, he has taken to coaching and would consider it as a second career.
"I love being here," Halladay said. "I definitely want to keep doing it. I think maybe this first year [after playing], I want to make sure that I get to spend the time that I want with my boys and my wife, and that's my priority. Once I see how things work, yeah, I'd love to continue to do it and if I have more time, do more. I'll always continue doing it. It's just a matter of starting to figure out how much I can do. Once the kids are [grown up], maybe it's something to do full time."
One thing Halladay is certain of is that he's in the right place on the opposite side of the white lines at the Carpenter Complex.
At 36, Halladay is younger than some of the pitchers he's working with (former Toronto teammate A.J. Burnett is 5 months older). But his body betrayed him in the last two of his four seasons with the Phillies, limiting him to 38 starts, with two trips to the DL and shoulder surgery. He is content in retirement.
"It was the right decision for me," he said. "I felt it was the best option and the only option. I still feel good about it. And I'm enjoying doing this part of it right now. It's been a good change."
Halladay said he wouldn't be caught sneaking off to pitch a private bullpen session to stage a comeback, even if he does feel the itch on occasion.
"I long-tossed with A.J. yesterday," he said. "That'll hold me over for a few weeks."
On Twitter: @ryanlawrence21