He couldn't take a plea and still play for Illinois. If he would have plead to a misdemeanor he would have been dismissed from the team.Once he's convicted in a criminal trial or took a plea deal, she could have launched a civil case for damages. (That second part is important - a plea deal would have left him open to a civil suit he probably would have lost or been forced to settle.)
Also if you're found guilty in criminal court, you're guilty in civil court effectively speaking.
The chain of events she was hoping for was he got suspended, once that happens he's desperate to play again so he agrees to a plea deal (at the time a misdemeanor), then gets found guilty or settles in civil court because the bar is much lower.
The suspension was the key to this plan, that's what triggered the text. Without being suspended, he has no reason to make a deal. They couldn't imagine he'd take the University to court and win for his right to play.
His only path to playing was the charges being dropped or the legal injunction.