2 major league caliber SS are currently on the waiver wire.
Shane Forrest has been horrid this season. Last season in a platoon role he was not half bad. Decent glove that won't bury you. OK bat. Not much chance of loosing on that claim.
In the last year of his contract Felipe Veras has something to prove. He is getting older and has lost a step but he is still pretty good defensively. While his bat was Belliard like last season and this season is worse, he was a .300 hitter in season 16. He also had 15 homers. Add in some good SB stats and I could see him finding a home in SD.