Scott broke his finger three weeks ago, apparently while slamming a car door, but has kept the injury quiet until now.
"Unfortunately I had to miss Jack Nicklaus' tournament last week due to a minor illness that set me back a week," Scott said on his blog, "however I am feeling better."
The Australian is scheduled to play the first two rounds at the Open with world Nos. 1 and 2, Tiger Woods and Phil Mickelson. Woods is recovering from knee surgery and is expected to appear in his first tournament since The Masters.
Scott hasn't played since the Players Championship, where he tied for 54th.