Admittedly, the prospect of coming face-to-face with a bloke with a wild look in his eye and wielding a snooker cue in a poorly lit room is enough to test the mettle of most people. It is, of course, the pace at which the defending champion is able to start matches which his opponents find most intimidating.
It is a feeling which Hendry understands well. A seven-time world champion, the Scot dominated the green baize - not least while winning five consecutive world titles during the 90s - and was acutely aware that many of his opponents struggled psychologically to stand up to him.
He has acknowledged that O'Sullivan is able to exert a similar influence in matches and maintains that pressure on those he plays by seizing control of the table early. The Scot is adamant that the only way other players stand a chance is if they too make an immediate impact.
"I think other players are afraid of him now," said Hendry, who retired from the game two years ago. "It's what I had in the 90s and it's a great feeling when you know people are scared of you. It's all about what Ronnie has got as well, it's something that I had in my prime.
"He starts so quickly and doesn't really give these players the chance to get into the match. He stops players from playing their natural game and straight away they're on the back foot because he gets out of the blocks so quickly.
"The only chances these players have got is if they can start like Ronnie. That's hard to do. When you're intimidated, as it seems they are, it's not easy to beat him."
That speaks to the expectation that O'Sullivan will add to his five world titles, as well as the influence the Englishman holds in the game despite declining to play in a single major tournament last season. It was a decision he took so as to spend more time with his family and two young children.
Indeed, the 38-year-old player - who will open his Dafabet World Championship challenge today against Finnish qualifier Robin Hull - returned to Sheffield without much in the way of competitive action and still cruised to the title. Hendry expects the Englishman to retain his trophy this year.
"In my eyes Ronnie is the clear favourite," he added. "He's a level above the rest. He's the only winner, really. Ding [Junhui] has won five titles this season but you only have to look at what Ronnie did too him in Wales [a dominant 9-3 victory in the final]. And then there was the final of the Masters where Mark Selby has done so well, but you just have to look at what Ronnie did to him [won 10-4].
"Last year with Ronnie, we didn't really know how he was going to perform because he hadn't played all year - and he won it. The big thing with Ronnie now is that he only plays when he wants to play. That's making him happier as a person and he's enjoying his snooker a lot more."
It was a sentiment echoed by O'Sullivan, who is looking forward to stepping out at snooker's spiritual home once more. "I had started to believe I needed to retire as I could no longer play at the level I wanted to but I am proving myself wrong," he said.
"Remember I didn't play one tournament before the Crucible last year. I maybe got away with one, but it gave me perspective and showed me what was possible."