The 37-year-old, who took a break last November to battle personal issues, will return to defend his world championship title in April.
"I think there will be a mixed reaction among the players. Some will think it adds to the tournament. Others will say it takes the limelight away from them," he told ITV4.
"I like Ronnie, he is a lovely man to talk to, but he can be extremely frustrating.
"It is good news that he is going to play. There will be a lot of interest to see what shape he turns up in, because a year out of the game is a long time."
O'Sullivan's absence has seen him drop to 24th in the world rankings.