It follows to closely to Bakers trend to just "wink, wink" it away. He's been too good this year to just sweep him to the DL to make room for Chap and Bailey. If you're closing in on the playoffs, don't you want the best pitchers on your roster available, whether it be starting our out of the pen?
Chapman and Bailey as of now are better than Leake. Leake started off incredibly strong but as of the past couple months he has come back to earth. One theory is the league has adjusted to him but also he seems to have lost a little bite off his fastball. The opinion around Reds country is he doesn't have the endurance yet to last an entire MLB season.