Ronnie O’Sullivan says Mark Selby needs to "get over" his defeat in last year's incredible World Championship semi-final.
O'Sullivan pulled off a spectacular victory over Selby at the Crucible last August, winning three frames in a row from 16-14 behind to claim a 17-16 triumph and reach the final, where he saw off Kyren Wilson for his sixth world crown.
Selby accused O'Sullivan of being "disrespectful" with some of the shots he played in the immediate aftermath of that match, with the bad blood appearing to spill over into this season.
For his part, O'Sullivan believes Selby has been a "bad loser" and thinks that Sheffield encounter has altered their relationship.
"I didn't realise that result had affected him as much as it had," O'Sullivan told Sporting Life.
"Sometimes you can want something too bad, and then it's hard to brush off a defeat, let alone a defeat how he felt like he was defeated.
"After listening to his after match interview, it sounded like he was a bit of a bad loser really. He didn't really take it well.
"I was a bit surprised. I thought he would have given me a bit more credit for hanging in there and playing three amazing frames at the end and getting the victory. It seems he didn't take it in that spirit.
"That's for him to get over. It doesn't seem like he's able to get over it really. They can be tough matches, I've had one or two of them in my career. They linger on for a bit. Hopefully he gets his head around it and moves on from it."
Asked whether he thinks the nature of his comeback win had rattled Selby, O'Sullivan said: "Oh yeah. A hundred per cent. I didn't realise at the time, because obviously you're on such a high and you've won, but actually if you were to sit down and listen to his interview and listen to some of the things he's said, you'd have to go, that's coming from somewhere. It's obviously bothered him to a certain extent.
"Listen, it would bother me I think, if I had one hand on the trophy, and all of a sudden someone has just come along and taken it away from you.
"It's not an easy one to get over, but until he gets over it and it's properly put to bed, it's a little bit difficult. I suppose it has changed the relationship in many ways because it's affected him.
"I kind of understand where it's coming from, but I don't really want to get involved in that sort of dynamic really. I just want to enjoy my snooker, go to tournaments. I'd love to do well at a tournament, but I'm not going to let a defeat or a game affect my mood, or the way I look at the game or look at a player. I would never let someone have that power over me. I wouldn't want that.
"I'd rather he'd won, been happy, and he would have been in a good place. Until he gets himself through that, I don't know. It's something he needs to get over for him to move on."
O'Sullivan's Sheffield success last summer was his first for seven years, and put him just one world title behind Stephen Hendry in the standings.
The 45-year-old goes into this year's tournament, which starts on Saturday, as one of the fancied players again. But O'Sullivan believes Judd Trump is a worthy favourite, and also thinks Neil Robertson's policy of giving some events during the season a miss might work in his favour for the 17-day marathon.
Asked if it was fair that bookmakers rated Trump as the most likely winner, O'Sullivan said: "Absolutely. How can you go against what he's done in the last two-and-a-half years? He's been by far the best player.
"Listen, he plays in every event. He wins a lot of events. Will he go to Sheffield having shot his bolt if you like, in a way? Someone like Robertson, who is equally as good, he's probably plotted his season around trying to be ready for Sheffield. He's probably the best all-round player in the game, I would say he's taken over from John Higgins in that department. Has he timed his run for the line better? Who knows? These are all the exciting permutations.
"Do you go for the man who has saved himself and focused his goal on winning the World Championship, which is Robertson I would say? Or do you go for a guy like Trump who says, do you know what, I'm going to play every week, I don't care what tournament I'm in, I just want to play, I just want to win. Will that come through as a strength?
"If those two met, it would be fascinating. Judd is more the explosive player, but then he can go missing a bit. Robertson is much more methodical, he plays a much more consistent kind of style. They're both very dangerous players."
Eurosport pundit O'Sullivan has fared pretty well himself this season, reaching five finals. But he's surprisingly lost them all, with his last tournament success being that World Championship victory eight months ago.
The Englishman insists he's not looking beyond the last eight at this stage, saying: "There's a lot of snooker to be played to get to the quarter-finals, there's a best of 19 and a best of 25. If I was to get through them, you've got half a chance.
"Two weeks ago I would have probably said I've got absolutely zero chance. All season I've been in and out, I've made five finals but I've played every week. If you're going to play every week you're bound to do well in some tournaments, whether you've played well or not.
"The World Championship is a lot different. You want to try and find some sort of consistency in your game, which I haven't found through the season. But on the practice table the last few days it's been a little bit better. Whether that's enough to carry me through to have a good run in Sheffield, I don't know.
"If someone was to give me a quarter-final and I didn't embarrass myself, and I was involved in some quality matches, I'd go, you know what, that would probably round the season off quite well.
"But if I was to get to the quarter-finals, who's to say my goals and aspirations of winning it wouldn't increase. I would love to get through one or two rounds and see where we are then. If I was to get through to the quarter-finals, then you've got half a chance."
This year's tournament runs from Saturday April 17 to Monday May 3
Coverage will be live in the UK via BBC and Eurosport