While the team has displayed both attributes, it's done so while also suffering through stretches -- that at times lasted minutes, other times affecting multiple games in a row -- of inconsistent levels of play.
Earning the Maui Invitational title, winning at Gonzaga and overcoming a 2-7 start in the Big Ten were just a few of the occasions Groce expressed pride in the effort spent and the backbone displayed by his players.
Friday's 80-64 loss to Indiana in the second round of the Big Ten Tournament quarterfinals offered a little bit of most every word that's been used to describe the Fighting Illini (22-12).
The Hoosiers (27-5), eager for revenge after losing earlier this season in Champaign, jumped out to a 16-5 lead early, establishing themselves as the aggressor in front of pro-Indiana crowd in the United Center.
Frankly speaking, the Illini were a struggle offensively from the opening seconds.
"When you go against someone like that you got to force them to take tough shots and I think we did a great job of doing that," Oladipo said.
"They were really locked on our shooters," Groce said. "I mean heavy. That took some time for us to get adjusted to, even though we encouraged them to do that, calling some things and trying to take advantage of that. I thought it was good on their part. I thought they defended well."
With Indiana's intentions made clear, that Paul and Richardson weren't going to get many open looks, Illinois needed other options to pan out. It didn't happen.
As a team, the Illini shot 7 of 27 (25.9 percent) and 1 of 6 from the 3-point line. Furthering the frustration, some of the misses were from point blank range.
"They were right there," Groce said of the misses. "You can't draw up a play to get a better shot than those four or five layups. We got to convert them."
That Indiana's lead was 35-21 was a small victory to Groce. And it was resiliency on the defensive end that kept the game from getting out of hand early.
With shot after shot missing the mark, the Illini, "controlled the controllable," according to senior forward Sam McLaurin. They played defense as best they could to limit the damage.
While the Hoosiers shot nearly 40 percent, they missed 7 of 8 from downtown. And as a team, Indiana committed 11 turnovers and scored only four transition baskets.
Trailing 14 at the break is never a good thing. But when your team plays as a poorly offensively as Illinois did, it's the best a coach can hope for.
"It could have been really ugly had we not defended like we did," Groce said. "That's a sign of being mature, that we didn't tie our defensive effort to how things were going for us on offense in the first half."
In the second half, Illinois showed it's toughness. Or maybe stubbornness is more like it.
Over the course of the first 11 minutes of the final period, the Illini pulled to within 10 on nine separate occasions. Eight of those times, Indiana pushed the lead back to 11 or 12 or 13 or 14. But the Illini kept coming back, hanging around and desperately trying to get the deficit to single digits.
Finally the Illini broke through, with two Richardson free throws with 8:20 to play.
It's as close as Illinois would get because while the offense clicked, the defense dissipated.
Said sophomore Tracy Abrams of the offensive change, "I would say if anything our guys just playing together and trusting each other and trusting the system."
So while Illinois more than doubled it's point total from the first to the second (21, 43), the Hoosiers were also an ideal plus-10 (35, 45).
In the second half, Indiana had nine offensive rebounds and shot 65 percent from the field.
"Defensively we weren't able to stop them in the second half," Groce said. "I thought they got too many layups, they got baskets in transition."
So, the first half saw resiliency on defense to keep the game within reason. And the second half offered a tough team who refused to go away by battling on the offensive end.
But a high level of production on both ends of the floor never happened at the same time.
"When you're playing Indiana, you got to be good in both, on both offense and defense, both halves," Groce said. "So I give them a lot of credit. They made a lot of plays."
Following the game, Groce was encouraged by the fact that Paul and Richardson spoke to their teammates about the consistency needed in order to win games of the magnitude of Friday's. During the post-game press conference, Paul, who finished tied with Abrams with a team-high 16 points, echoed what he told his peers.
"The takeaway is if you compete at a high level, you can compete with anybody in the country," he said. "I felt we came in with the mindset that we can win all these games. We went through some rough stretches throughout the game and I felt like once we put two halves together we'll be in a good position. Sometimes one half our defense might be off or the next half our offense might be off. Once we put two halves together we're going to be a force to recon with. And I think we still, we're going to continue to look forward to Sunday, because I feel like we have a lot of basketball left."
Paul, of course, was speaking of the NCAA Tournament. The Illini, who missed the Big Dance last season, await Sunday's word to find out what team is up next.
Friday's loss to Indiana, while lop-sided on the scoreboard, did offer stretches of what previously led to success during the last four months. It's the inconsistency that accompanied everything else that just won't do any longer moving forward.
That's because the team's next loss will be it's last loss.
"We played pretty good basketball (Friday)," Groce said. "We're capable of playing really good basketball.
"These guys care a lot about one another and they care about Illinois and about our team, about doing well, about playing well. This time of year that's really important."