"If there's a connection there between my performance and all of those Clint movies, I think it's unconscious," says Bacon, who stars in the film with Sean Penn, Tim Robbins, Laurence Fishburne, Laura Linney and Marcia Gay Harden.
"Honestly, it never really occurred to me that it would be the type of part that he would play, that there are similarities.
"Now I get it, after the fact," he adds. "Here's a guy who plays it very close to the vest and has a troubled past. . . . But you don't see him really dealing with it demonstratively, and that's a real Clint kind of thing."
Bacon, who is 45 and has made close to that number of pictures since leaving his hometown of Philadelphia in the mid-'70s, jumped at the chance to work with Eastwood. The actor-filmmaker is famous for shooting fast and cheap, and Bacon - who directed his wife, Kyra Sedgwick, in the '96 indie Losing Chase and will holler "action!" on his second feature, Loverboy, next month - was keen to watch, and work, with the master.
Did he and Eastwood talk over Bacon's role, or the themes - guilt, loss, retribution - that churn under Mystic River?
"We didn't discuss much, to tell you the truth. You know Clint, that's just really not his style to talk talk talk. It's more shoot shoot shoot.
"Normally, you have something like two weeks' rehearsal on the schedule. There's a lot of discussion of the characters, a lot of blocking the scenes, running through the script, and long sessions where your clothing is approved, and makeup and hair tests. On a studio picture, that's really the rule.
"So I spoke to the producer and he said, 'We start shooting on Monday, so if you want to come up on Sunday, that's fine.'
"I was like, 'Well, I guess I should maybe get there a couple of days before, don't you think?' '"
Bacon did spend time researching his role, talking to Dennis Lehane, who wrote the novel that Brian Helgeland (L.A. Confidential) adapted, and hanging out with a Massachusetts State Police homicide investigator. And Penn suggested that the cast get together and do read-throughs.
"Clint certainly approved all of that," Bacon says, "but he had no interest in being there. Then on the day, we just showed up and did our work."
The actor, who lives in New York with Sedgwick and their two children, Travis and Sosie, found Eastwood's style liberating.
"Look, it's a terrible thing to say, but sometimes I feel like the best direction I can get is to just leave me alone and let me do my thing. I've been doing it a long time and I have really clear ideas."
He adds: "When I first became an actor, I had this idea that a director was going to make me good. That it was going to be something like an acting teacher, that there were going to be great words of wisdom they would impart that would transform my performance from run-of-the-mill to brilliant.
"Truth of the matter is, that's just not the way it works. They put you in the part and then a lot of it is really up to you. . . . That's not to say I haven't had directors who have really brought something special [to the project], but that's more the exception than the rule."
In addition to Eastwood, with whom he shares a love of music (the director, a pianist, wrote the Mystic River score; singer-guitarists Kevin and Michael Bacon will release a live Bacon Brothers DVD and double CD on Nov. 11), the actor has had some other impressive bosses: Barry Levinson (Diner), Rob Reiner (A Few Good Men), Ron Howard (Apollo 13), Curtis Hanson (The River Wild), and Oliver Stone (JFK). He'll be seen next in In the Cut, directed by The Piano's Jane Campion and due out Oct. 24. Bacon has a small, but pivotal, role as Meg Ryan's jilted boyfriend - a mentally unstable guy in hospital scrubs whose lurking presence is creepy and, perhaps, deadly as well.
And then there's The Woodsman, the picture Bacon shot in Philadelphia earlier this year.
"It's about a convicted child molester who's getting out of prison after 12 years and trying to pull his life together," reports Bacon, who plays the child molester. Nicole Kassell directed, and Benjamin Bratt, Mos Def, Eve and David Alan Grier costar.
"It's a movie about a sick man trying to get well," he says. "It's one of those things that fell into my lap and everybody was like, 'Are you sure you want to do this?'
"It's a very low-budget thing, but I found the story compelling and I'd never seen anything quite like it before. I've never seen a child molester be a lead character in a movie. I'm sure there's going to be a [fire] storm surrounding it, but it came out really well."
The actor, whose father is legendary city planner Edmund Bacon, said coming back to shoot here was a bonus.
"I left Philadelphia when I was 17, and except for some family visits, I haven't really spent a big chunk of time there for 25 years or whatever. So, to go back and really live there for five or six weeks was just great. The city seems so vibrant, better than ever. I grew up in Center City and I stayed in Center City when I was making the picture.
"When I was a kid, there were no restaurants to speak of. You know, we ate at Freddy's Pizza, and sometimes as a special treat we'd go to this pharmacy where we could get hamburgers," says the actor, who has done some work with the Greater Philadelphia Tourism Marketing Corp. folks. "But now, it's like you walk out of the hotel and there's just insanely great food and people hanging out everywhere. It's really alive."
After playing a stalker in scrubs, a convicted pedophile, and working in the dark and troubling Mystic River, Bacon says he's ready for a change.
"I'm hoping that the next time that I get in the saddle I'm riding the white horse. . . . You know, I'd love to do something romantic, something heroic."
Does he feel like the intense, menacing roles he's had through the years have branded him?
"Look, Hollywood is all about typecasting," he acknowledges. "I learned that right after Diner. I would get the weird-buddy scripts, the alcoholic, weird buddy. People are afraid of taking a shot that somebody can do something different than the last thing they did. Especially if the last thing you did makes money, then they definitely want to see you do the same thing.
"So you have to fight against that, and that's what I've done my whole career. I really try to keep switching it up, because that's what feeds me. . . . And sometimes it's hard, but something always comes along."
Contact movie critic Steven Rea at 215-854-5629 or email@example.com.