He never let Phil forget that -- not through the teenage years when he would think about quitting, and not through the tough times in the Minors. Now that he has become one of the better lefty relievers in the big leagues, Coke will never forget what his dad did for him.
"It was a long process, and I really had to work hard to get to where I'm at," he said. "If it wasn't for my dad constantly pushing me in the right way, I don't think I'd be here."
When Doug was coaching his older sons in tee ball, he would let Phil hit, even when he ran the bases in the wrong direction once after a home run. He would play catch with him all the time until Phil began throwing too hard for him and hurting his hand.
Doug spent 18 years working as a corrections officer in California, some of them housing some of the nation's more notorious criminals. When Phil was in high school, his dad was hospitalized after a stress-induced health scare at one facility.
With that type of day job, Doug would've figured to fit the type of strict father who would be forceful in keeping his kids in line. To hear Phil tell it, he could yell and scream at his kids when he had to, and Phil's antics on occasion would deserve it at times.
More often, though, he would use mind tricks to get it done.
"There were two years I contemplated not playing baseball," Phil Coke said. "There were back-to-back years when I was in sixth and seventh grade, and my brain's starting to be like, 'Well, that's a lot of work. I don't know if I want to do that.' And my dad's like, 'Well, tell you what: Why don't you go to practice and see how it feels? See if you change your mind.'
"The result ended up being exactly what I expected from my dad, but I didn't know it at the time. He has always drilled in me and my brothers' heads, 'If you start something, you finish it.' Well, I went out for practice, so therefore, I started it. I came home that day and I'm like, 'Yeah, I'm not feeling it.' He's like, 'Well, that's a real bummer, son, because you started it. You better finish it.' And he did it to me two years in a row. I ended up having two really good seasons those two years."
Years later, when Phil had grown up and gone into the Yankees farm system, his dad's advice came in handy again after a miserable start in 2008.
"The first month of the season was terrible for me, four or five starts," Phil Coke said. I called my dad and I'm like, 'Man, I don't know if I'm cut out for this, dad. I don't know if I can do this.' He's like, 'Well, fine. If you're not playing, come home.' Knowing my dad the way I know my dad, I look at the phone.
"I'm like, 'What did you just say to me?' He's like, 'If you're not good enough, then come home. Quit. And I'll back you 100 percent over that decision.' I told him that wasn't going to happen. And he said, 'Well, good. That's what I want to hear out of you. Go have fun, because when the game's fun, you're really good at it.'"
Phil recovered and made it to the big leagues that September. He still came home in the offseason to work with his dad, who went into business for himself doing construction.
Doug has another memory that helps his son to this day. It was the day his son tried to get autographs at an A's-Padres game in 1998 at Oakland Coliseum. After another player blew off Coke as he waited for autographs behind the visiting dugout, Steve Finley told him he would be signing autographs on their way out after the game. Sure enough, he did.
That story is a reminder for Phil to not get so preoccupied as to turn down an autograph for a kid. That lesson stuck, too.
With two sons having served in the military and another in the Majors, Doug can sit back and enjoy his family now. He won't miss the Tigers in the Bay Area, and every so often he'll make the trip east to Detroit.
It's hard to miss him at Comerica Park. He has a jersey with the name "Phil Coke's Dad" on the back.
"My dad is a very successful dad, in my mind," Phil said. "He may not have done everything the way he wished he would've, but where others may have failed, he has succeeded greatly."