I can add to this.
When Groce landed in Illinois, the 7 foot center Meyers Leonard decided to go pro. Meyers would have been a junior and averaged 13 pts/game his sophomore year, but he was not even close to a finished product. However, nobody could blame Meyers for leaving because he ended up being a first round pick in the NBA draft and his Mom needed lots of medical help. So getting paid was a high priority. But by him leaving, Illinois had a huge whole in the roster which Groce had to try to patch with a grad transfer. Years later Meyers Leonard was coming around the practice facility. I guess no harm, no foul. Personally, I thought not only would one more year at Illinois help his fellow teammates make a run in the tourney, the added experience at that level would have done wonders for Meyer's confidence and footwork development. Anyway, Groce has a healthy attitude towards these kinds of situations and he's a long-term relationship builder.