The 19-year-old potter was picked out as a star for the future by winning the Rileys Future Stars competition in 2010, a nationwide hunt to find the best junior player in the UK.
Part of his prize was a series of training sessions with the five-time World Champion, but since turning professional the pair have never met in competition.
But next Tuesday, Walker will face O’Sullivan in the qualifying rounds for the International Championship at Barnsley Metrodome.
“I’m really looking forward to playing Ronnie, I can’t wait,” said Walker, who is ranked 89th in the world.
“I spent a lot of time practising with him in 2010 and learned a lot from him.
“I played six matches against him and the first time I was nervous, but after that it didn’t bother me.
“I didn’t beat him but the closest match was 9-7. I have improved a lot since then as a player, and if I play well on Tuesday I’ve got every chance of winning.
“I think spending that time with him will benefit me because I won’t be worried about who I’m playing, I’ll just be focussed on the balls.
“I still speak to Ronnie when I bump into him at tournaments and he always has time for me.”
Their match cues off at 2.30pm, with qualifying rounds on Tuesday and Wednesday, featuring 128 of the world’s best players. The 64 winners will then progress to the final stages of the world ranking event in China.
Walker has made an impressive start to the season, reaching the last 32 of the Wuxi Classic in China and qualifying for the final stages of next month’s Indian Open in Delhi.
“It’s great going to new countries to play snooker,” he added.
“This season I’m trying to get into the top 64 and do as well as possible in the European Tour events.”
Sheffield’s Adam Duffy faces Michael Wasley (2.30pm, Tuesday), while Peter Lines, from Leeds, takes on Hammad Miah (7.30pm, Tuesday).
Entrance is free to the Metrodome for fans, with players like Judd Trump, John Higgins, Mark Selby, Neil Robertson, Ding Junhui, Steve Davis and Jimmy White on show.
On Thursday, October 3, it’s the qualifying rounds of the World Seniors Championship.