Palmer, a 12-year veteran, underwent surgery in November after tearing his ACL in Arizona's Week 10 game against the St. Louis Rams. He told Werder that he expected to take part in Cardinals offseason workouts, including mini-camp and training camp.
Palmer reportedly began running again last week and Arizona general manager Steve Keim said the 35-year-old's rehabilitation was preceding well.
"He's awesome," Keim said. "He came in, I believe it was yesterday and I talked to him at length, he's more energized than ever and he looked fantastic."
"And I know he's at a point in his rehabilitation process where he's doing some running and he's ahead of schedule. And again, he's more energized than ever."
Palmer's most recent knee injury was the second of his career, after the severe ACL tear he sustained during the 2006 season.
Before his season ended in November, Palmer had already missed three games for an injury to a nerve in his shoulder. In the six games he did play in, he completed 62.9 percent of his passes for 1,626 yards with 11 touchdowns and three interceptions.
He led the Cardinals to a 6-0 record in games he started.
When Palmer, who has thrown for 35,365 yards and 224 touchdowns in 144 career games, returns to offseason workouts will still be decided by Cardinals training staff.
Arizona finished last season with an 11-5 record and in second place in the NFC West. The Cardinals lost to the Carolina Panthers in the NFC Wild Card round.
- Christopher Woody