Breaston had expected to return last weekend in Seattle but was held out because of the wet conditions. He has missed three games following arthroscopic knee surgery.
Whisenhunt also said he is considering activating inside linebacker Gerald Hayes and rookie outside linebacker O'Brien Schofield. Both have been out all season, Hayes following back surgery and Schofield after reconstructive knee surgery.
Arizona starting outside linebacker Clark Haggans has not practiced this week because of a groin injury. If Haggans can't play, his replacement would be second-year pro Will Davis, who played 24 snaps in relief of Haggans in Arizona's 22-10 loss at Seattle.
"I've been preparing every week the same way, like I'm one play away," said Davis, a 2009 sixth-round draft pick out of Illinois.
Breaston said he was tired of talking about his injury situation but, nice guy that he is, did so anyway.
"It's tough but it comes with the game," he said of missing so much time. "I was looking forward to being back last week so that's disappointing. I just want to play some football again."
Breaston was injured in the second game of the season at Atlanta but tried to play through it the following week against Oakland. That's when the decision was made to scope the knee.
"It's sore but that's expected," he said. "I felt good out there running. I'm getting my speed up, getting my burst together. I'm really ready to play on Sunday."
Breaston has 132 catches for more than 1,700 yards the past two seasons and has been sorely missed by an offense that ranks last in the NFL and has an undrafted rookie, Max Hall, at quarterback.
"You've got a veteran guy that's made a lot of big plays for us that you have confidence in," Whisenhunt said. "I know Max got a number of reps with Steve in camp so there's a comfort factor there. It's always good when you have a player like Steve come back. That can only help us."
Hayes and Schofield started practicing only last week. If either is activated it would require a roster move.
Hayes is a four-year starter who had been on the physically unable to perform list.
"We're working him in," Whisenhunt said. "He's got a couple of packages that he's playing in and I think he's pretty close to being ready to go."
Schofield, who had 12 sacks as a senior at Illinois, was considered among the top players at his position in college but blew out his left knee while practicing for the Senior Bowl. The Cardinals selected him in the fourth round, knowing they would have to wait for his injured knee to heal.
Schofield said he thought he might miss the entire season.
"But they gave me an opportunity to come out there and practice and I was like 'Man, it felt good," he said. "I got hit on the knee a couple of times and I kind of paused and thought about it, 'OK, no pain,' everything feels good."