The 20-year-old was ruled out for six weeks after fracturing a metatarsal bone in his right foot during Manchester United's 3-0 defeat at champions Chelsea on Saturday. England play their first Group B game against Paraguay on June 10.
"I'll be coming in (for treatment) every day and trying to give myself the best possible chance," Rooney told MUTV on Tuesday. "I'm obviously devastated to have broken my foot at this moment in time, it really is horrible.
"But I'm in great hands at United and I know with the physio team I've got behind me here that they'll be able to give me the best possible chance.
United manager Alex Ferguson said on Monday he thought it unlikely Rooney would play any part in the finals in Germany.
Ferguson also voiced his concern over the media hysteria that greeted Rooney's injury and the player himself said he wanted to be left alone to recuperate.
"I'd like to thank everyone who's sent me messages and supported me," he said.
"But it's now important that I have some privacy and the press leave me alone as I try to get myself fit."