The safety and nose tackle both suffered ACL tears during the 2013 NFL season, while Mathieu is also recovering from an LCL injury.
The Arizona Cardinals head coach told the team's website: "I'm not going to hurry them. We have plenty of time. If they aren't ready for the first day of training camp, which I doubt anyway, because I've never thought that.
"I had October 1, or after the [bye week] as the target date for me personally. If they do something better than that, God bless them."
The Cardinals have an early bye week in week four of the 2014 season, and will face the Denver Broncos in week five.