Fitzgerald sprained his left MCL during last Sunday's victory over the Detroit Lions. On Thursday, he said his knee was feeling ''a little bit better" but did not practice for the second straight day. On Friday, the receiver said he was "optimistic" about playing in Seattle.
Fitzgerald currently holds the longest active streak among NFL wide receivers, as he has started 71 consecutive games. The 31-year-old has not missed a game since Week 13 in 2007.
In 10 games this season, Fitzgerald has 46 catches for 658 yards and two touchdowns.
The Cardinals (9-1) play the Seahawks (6-4) in Seattle at 4:05 p.m. ET on Sunday.
- Sarah Barshop