"It's more personal in nature now, but it was personal and professional in nature prior to coming here," Groce said.
Groce's Illini (13-2) play Matta's No. 8-ranked Buckeyes (11-2) today at 1:15 p.m. Aside from a preseason scrimmage last season, the matchup marks the first meeting between the two men. When asked about his mentor earlier this week, Groce first expressed his appreciation.
"I've said this numerous times, I wouldn't be standing here with this opportunity to be at the University of Illinois without him," he said.
Then he got down to business.
"He's competitive, I'm competitive," Groce said. "When that balls tipped at 1:15 (today) I won't think a whole lot about that. He's not either. We're going to get after it, just like his club will."
Todd Lickliter is the connection between Groce and Matta.
Lickliter was an assistant at Butler for the 1988-89 season, a team that Matta led in assists and three-point percentage. Lickliter then moved on to Danville Community High School, a squad that featured a scrappy guard by the name of John Groce.
A decade later, Groce joined Matta's staff at Butler, a group that included Lickliter (who later took over the Bulldogs and Iowa).
How's that for a coaching circle?
Now over 10 years removed from that first season together, Matta offers nothing but praise for Groce. The two were together for an Elite Eight run at Xavier in 2004 and took Ohio State to the national title game in 2007.
"John is a very, very hard worker," Matta said. "He's a very intelligent guy, and he kind of -- he gets it. He understands the climate of college basketball, and I think that's what you've got to have."
After so much time together in the same huddle, it's safe to say the two coaches will draw from the same bag of tricks. That's not advantageous for either team, according to Groce.
"We know certain things about how he thinks and how they play, but, you know, he can say the very same thing about us," he said.
"We know each other well, but at the end of the day players make plays. I feel like we'll put our guys in a position to be successful. Our staff and assistants have put together a good game plan. I'm sure his have done the same. At the end of the day we have to execute the game plan and get buckets."
For Matta, the chance to see one of his former assistants leading a program in the Big Ten provides a sense of pride.
"The thing I always want for our guys, is I always want what's best for them and their families," he said. "Obviously this is a great opportunity for John.
"I know John feels the pressure to build that program. I think he's up to the challenge."
After paying his proper respects, Matta then showed his true colors, in true coach's speak fashion.
"We're not playing in the game," he said. "I think from that perspective, I hope John wins every game except when we play them."