Monahan, who recently missed a pair of games, thought to be in the 'healthy' scratch category, was excited to be part of a long playoff run this year. As a three-time 30-goal scorer, he knew he could step up and contribute when the games matter most.
Instead, the situation became untenable - and he could no longer play through the pain.
Forget hockey.
In times like this, you can't help but feel gutted for Monahan, the person.
"Sean is one that plays through a lot of stuff without telling a lot of people," Treliving said. "I do want to say that. I know Sean has faced a lot of criticism and I think a lot of it is... I think there was a lot of (crap) out there, to be honest with you. This guy plays through a lot of things and for people to challenge or question him, I think is wrong. Most people out there couldn't play through a third of what he has. And he keeps it to himself. This isn't stuff where people are forcing him out on the ice.
"I don't know how it's been bothering him. He's been getting treatment like everybody's been getting treatment, and then in the last couple days, he said, 'I've got a problem here.'
"Once you say you've got a problem, you go and get it looked at, and it needs to get taken care of."
Hockey players have a habit of gritting their teeth and 'sucking it up.'
But what Monahan did - playing through pain, never missing a practice, and keeping his quandary out of the public eye, while having every excuse not to - is proof he's one of the ultimate team guys.
While it's unclear exactly how long it's been bothering him, No. 23 would never let that be an excuse.
He's a warrior, through and through.
A man who at the turn at the calendar, challenged himself in a new role, diligently worked at his craft, and pushed himself as far as his body would allow, all because he believes in this group and what they're capable of.
"Oh, unbelievable," Treliving said of Monahan's dedication and show of leadership. "You go in that room right now, there's 23 guys that love the kid. He wears a letter for a reason. He's had a different role, that's the best way to put it.
"He went about it with a smile on his face and went to work. Never complained, doesn't whine.
"'What can I do to help the team win?'
"That's what Sean Monahan's all about.
"And unfortunately, sometimes your body doesn't allow you to do certain things."