I don’t think this is true. He finished with 3 fouls. While he may have picked up a couple of fouls early (I don’t know) he wouldn’t have sat for 26 minutes because of that alone. He hadn’t yet been handed the role he has now.
Indeed...
He started the game, committed a turnover on our first possession, picked up a foul at 18:33, got an assist and made a 3, then was subbed out at 16:23 (ILL up 8-5).
He went back in at 14:00 (ILL 15-12), missed a 3, picked up his second foul at 12:05, subbed out at 11:46 (ILL 23-12), and did not return in the half (ILL 43-32 at half).
He started the second half, got an ORB followed by a turnover, then picked up his third foul at 17:47, and subbed out at 14:14 (UConn 52-39).
He came back in at 11:57 (UConn 60-43), missed a layup, left again at 9:53 (UConn 64-45) and never returned.
While he had some good stat lines against bad opponents before that game, he struggled against TT, Alabama, and UConn: collectively 22 pts (4-12 from 2, 2-9 from 3, 8-11 FT), 2 AST, 5 TO, 11 REB, 8 fouls (fouled out vs Alab).
It's amazing how quickly the switch flipped for him a week later vs Tennessee on Dec 6 (an efficient 16pts and 5 AST 0 TO). He didn't really have a bad stat line until MSU on Feb 7. Maryland was an inefficient shooting night, but 7 AST and 0 TO made up for that.
Presumably the staff saw the role for him wasn't working, and rather than leave him in to suffer, limited his minutes, implemented a new role in practice, and let him cook.