But to Brad Ziegler, the Phillies first baseman is the guy who calls him "Ziggy" and beats him at the bowling alley. The A's relief pitcher knows Howard as the guy who lived with him in the same dormitory at Southwest Missouri State University. Howard's the guy who was Ziegler's roommate at Spring Training in 2004. And Howard's the big guy with the big numbers and big accolades who Ziegler simply calls a good friend.
"He's one of the nicest guys I know," Ziegler said before the A's took on Howard and the Phillies for the first game of a three-game Interleague series at McAfee Coliseum.
The 28-year-olds first met in college and quickly became friends through the baseball team, but Howard said it was harder to get Ziegler to talk than to get a hit off him during practice.
"He was very quiet and reserved," Howard said. "It took a couple years before he started coming out of his shell.
"By the time he got drafted, he wasn't afraid to trash talk. We taught him well."
Both players were drafted by Philadelphia -- Howard in 2001 and Ziegler in 2003. But even though the Phillies only gave Ziegler six innings in the Minors before releasing him, the A's pitcher said he did not expect facing the team who cut him loose to be anything out of the ordinary.
"It's actually motivation," Ziegler said. "They really didn't give me a good chance, so I feel like I want to prove to them I belong here."
He's also looking forward to possibly facing the man he hadn't seen in more than a year before Tuesday. The two text each other all the time, but there's nothing Ziegler's looking forward to more than seeing Howard in the batter's box.
"There will probably be a little extra adrenaline," Ziegler said.
Howard assures there will be much more involved.
"Of course, I'm going to go up with the same mind-set I would any other at-bat," the first baseman said. "But, you know, there's always going to be bragging rights."
Ziegler, however, thinks he's got the advantage because Howard has never faced his new side-arm approach.
"I faced him a ton of times in college and know his weaknesses," Ziegler said, "but he's never seen me throw this way."
One guy who's watched both players progress over the years -- Ziegler's father, Greg -- will be in the McAfee Coliseum stands. Greg flew out from Kansas City for the weekday series.
"He wanted to see Ryan play," Ziegler said. "And I guess me, too."
No matter the outcome of the college reunion turned Major League matchup, however, Ziegler will still be texting his buddy at the end of the night just as he would any other time.
"He's done things everyone has dreamed of doing," Ziegler said. "Being the big star that he is, it's never gotten to his head."
Jane Lee is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.