He confirmed during a conference call with reporters Tuesday that he was a regular in sanctioned tournaments until he reached the ninth grade, at which point he turned to football for obvious reasons.
I kind of grew out of the tennis body, said the 6-foot-3 Dieffenbach, now a Cinnabon shy of 300 pounds.
He said he was good at tennis, not great. That he possessed a big serve and one other attribute.
Surprisingly, he said, I was really good on the court. I got to every ball. I guess you could say I had good lateral movement.
That has served him well in football, helped the redshirt junior become a two-year starter at left guard. And he and his linemates figure to play an important role Saturday as the Nittany Lions (3-1), coming off the first of two byes in their schedule, open Big Ten play at Indiana (2-2).
Discounting the victories vacated under last year's NCAA sanctions, PSU is 16-0 all-time against the Hoosiers -- 16-love, as Dieffenbach might have said in his younger years. But this year IU, which employs the sort of brisk offensive pace that is so common these days, has moved the ball and put up points. The Hoosiers are first in the conference and eighth nationally in both passing offense (348.5 yards per game) and total offense (547.2), and second in the Big Ten in scoring (44.5).
The obvious countermeasure is to not only play sound defense but hog the ball and score points oneself. Coach Bill O'Brien, whose own team has been known to play fast at times, talked Tuesday about the importance of varying the pace and finishing off drives.
I don't think we can come out of the game with a bunch of field goals, he said.
To date, everybody has scored on the Hoosiers. They are allowing a shade under 33 points a game, which puts them 11th in the 12-team conference. They are also next-to-last in total defense (463.2 ypg) and dead last in rushing defense (247.8 ypg), with the latter figure ranking 115th among 123 major-college teams.
Particularly notable is the fact that Navy ran on its first 29 offensive plays against Indiana the second week of the season, and finished with 444 rushing yards on 70 attempts in a 41-35 victory.
That of course is music to an offensive lineman's ears.
It's always important to run the ball, Dieffenbach said. It sets up a lot of things on the offense, it burns clock and it's an important part of the game. We think we have some really great running backs and hopefully up front we can do our jobs and block well against Indiana and really get some running yards going.
The Lions ran for 151 yards in last year's 45-22 victory over IU, 135 of those by Zach Zwinak. But the bigger story was Matt McGloin's 395-yard, four-touchdown passing day. Three of his TD throws went to Allen Robinson, who had 10 catches for 197 yards in all.
Either way, the line figures to play a role. Working under veteran coach Mac McWhorter -- a terrific coach, Dieffenbach said -- the grunts spent their bye week brushing up on their technique, getting ready for the Big Ten slog.
I feel like we've been improving every game, Dieffenbach said. It's just something you really look for as an offensive line: You want to get better. You don't want to take any steps back. But there's always a lot of room for improvement.
Speaking of which, O'Brien called Dieffenbach one of our most improved players from last year during his weekly press conference Tuesday, after saying what he has always said about a guy known for his sense of humor: Every team needs a Miles Dieffenbach. And not just because he's funny and playing well, O'Brien added, but also because Dieffenbach continues to take care of business in the classroom.
None of that appears to be an accident. Dieffenbach said his father, George, has had a terrific influence on him over the years.
I've never met such a positive person in my life, Miles said of his dad, who retired from his coaching job at Pitt in January, after over three decades on the job. He's always encouraging me, wishing the best for me. He gives good advice. I couldn't wish for a better dad.
Not too long ago the younger Dieffenbach paid it forward, being among those to pass along a signed jersey to his coach at Fox Chapel, Bryan Deal, after Deal's 23-year-old stepson, Kyle Johnson, died of cardiac arrest during the Pittsburgh Half-Marathon in May. Johnson, whose demise was the result of a heart abnormality, was a 2008 graduate of North Allegheny and a 2012 PSU graduate.
I really wanted to do something, Dieffenbach said. My high school coach I'm really, really close with. I just felt like there was something I could do to help that family out. It was just really special. I just wish the best for them.