Rooney was left out of the squad that beat Schalke 4-1 in Wednesday's Champions League semi-final second leg after complaining of a tight hamstring during training on Tuesday.
Evra was left out of the starting XI for the game as United rested a number of key players with Sunday's game at Old Trafford in mind, but he came on as a substitute in the second half before taking a knock.
However, Ferguson told MUTV: "Patrice got a kick. I was ready to substitute him but he said he was okay.
"Wayne will be all right. I wasn't prepared to take a risk."
John O'Shea, who captained the side against Schalke, believes United can deny Chelsea on home turf and take a big step towards the title.
"We have shown a lot of experience at Old Trafford in big games," O'Shea said. "We have already played Chelsea at home in the Champions League, so we know we will have to play well.
"Chelsea have hit a bit of form but we know we are a good team at home as well."