They were the favorites to close for the Blue Jays and White Sox, respectively, but Janssen's DL trip and Jones' initial relegation to a setup role have dashed those hopes. Both pitchers could find themselves closing in the very near future, so there's no reason to drop either, but you may need a short-term fill-in.
In standard mixed leagues, Jim Henderson (73 percent ownership rate) and Huston Street (69 percent) are proven, solid options who could still be available. Tommy Hunter (61 percent) has only a minimal closing track record, but he has superb control and is a potentially sneaky source of strikeouts.
In deeper leagues, Sergio Santos, J.J. Hoover, Sam LeCure, Josh Fields and Chad Qualls are your best bets. All but Santos are members of closer committees, thereby lacking the value of a full-time closer, but each should chip in a few saves over the coming weeks.