The Fighting Illini (20-9, 7-8) twice led by eight points, but appeared to run out of gas in the second half as the Wolverines, according to Groce, were tougher down the stretch.
The loss ended Illinois' five-game winning streak, a run that occurred over the span of 14 days and could have potentially left the Illini mentally and physically exhausted.
"I'm not a big excuse guy, but let's put it this way, I do think the week bye was at a good time for us," Groce said. "A good time for us and our team moving forward, so we're thankful for that."
Illinois looks to start another winning streak today at 4:15 p.m., playing host to Nebraska (13-15, 4-11) at the Assembly Hall. The Illini defeated the Cornhuskers 71-51 Jan. 22 in Lincoln. Most recently Nebraska lost 77-46 to Wisconsin. Still, Groce expects a tough challenge.
"I think both of us are different. I think they've continued to get better," he said. "I know they didn't have a great game in Madison against Wisconsin. I can relate."
Enjoying the longest break between games since late-December, Groce gave his team a couple days off early in the week. The team returned to practice Thursday for a session that according to Groce, "had a lot of energy." Practice on both Thursday and Friday was short by design.
"I think it's important to get them fresh at this time of year," Groce said.
"I think the biggest thing this week was we were able to get freshened up mentally, physically."
Although a win Saturday would almost certainly lock up an NCAA Tournament berth, Groce continued to back his stance that improving on a daily basis takes precedence over wins and losses.
With the company line out of the way, Groce relented to say that the game stands out for a different reason. For five players -- D.J. Richardson, Brandon Paul, Tyler Griffey, Sam McLaurin and Kevin Berardini -- Saturday marks the last time the seniors will suit up for a game in Champaign.
Groce said the resiliency shown by the collection of seniors is what he's most proud of. It was a players-only meeting, organized by Richardson and others, held prior to the first Nebraska game that started the season turnaround.
Since that time, the Illini have gone from a team with a 2-7 Big Ten record to regaining the reputation as having the potential to beat any team in the country.
"They've had a little taste of what we all know as adults what life is about throughout their careers," Groce said. "They've had to deal with some ups and downs and have dealt with them in first class manner, certainly since the time that I've been here. Great, great to be around. Really fortunate that I've had the chance to coach them. Really appreciate their attitude and disposition, I've said that all along."
With the calendar flipping to March, Saturday's Senior Day is the first milestone of many to come in the month that's known for producing basketball madness.
Groce declined to comment on the NCAA Tournament, revealing that he's keeping his team from looking ahead to what may occur in the weeks to come.
"I've asked them not to think about that or talk about that," he said. "I'm in there with them, right in the foxhole with them.
"We've got to play better. That's kind of been our focus and we're going to stay with that for right now."