Well, not yet, but soon he will be. Wainwright,the Cards best starter, has been sidelined since since the beginning of June with a finger injury. He'll make his first rehab start in AA Saturday, and should be recalled soon after.
If healthy, Wainwright can be a solid addition to any fantasy team down the stretch. He was excellent before the injury, posting a WHIP of 1.09, a 6-3 record, and an ERA under 3.2.
Since the trade deadline has passed in most leagues, the only way you'll be able to add a player to your team is via the waiver wire. Since Wainwright's been out so long, that's where he probably is in most leagues, depending on how many DL spots your league allows. Before the injury, he was in the midst of putting together his second solid year in a row. He's worth monitoring from here on out.