Head coach Franco Smith faced a significant selection dilemma ahead of the Champions Cup last-16 tie, ultimately choosing Stafford McDowall at outside centre ahead of Jones. It proved to be the right decision, with McDowall delivering a man-of-the-match performance that justified the call.
Carolan revealed that Smith wrestled with the decision, even losing sleep over it, but was especially impressed by Jones' reaction after being informed - acknowledging his disappointment but continuing to support the team.
"Huw's a great pro," said Carolan. "He understands the situation. It's difficult. He had a really good Six Nations. It's a massive call. I don't envy the calls that Franco makes. It's tough. I think it does involve sleepless nights. Because you don't want to let anyone down.
"But I think when you see the work that Stafford does behind the scenes, from outside of our four walls, people might say, how can you not pick Huw Jones?
"He's in the World team of the year. But when you see what Stafford McDowall does for us, on our pitch here with our team, he adds so much value. He merited that Man of the Match award the other day.
"Huw's been brilliant. Again, he supported us really well last week. He was obviously disappointed. While you've got to wallow for a small period of time, he picked himself up and he prepared our team to be as good as we could have been at the weekend.
"He supported Stafford the best way he could be. He's a true professional player. He understands what Stafford brings as well. We'll see what happens this week."