Ohlendorf to DL, Xavier Cedeno returns to Nats; will Karns soon get another shot?

Right-hander Taylor Jordan has tossed a combined 125 2/3 innings in his first season back from Tommy John surgery. 35 1/3 of those innings have come at the major league level, where it appears he is there to stay. With starter Ross Detwiler likely done for the season with a herniated disc and a Jordan shutdown six starts away, who will the Nationals choose to be the fifth starter in the rotation? Ross Ohlendorf appeared to be the answer as a starting candidate. But Sunday he was placed on the 15-day disabled list retroactive to August 1 with right shoulder inflammation. Ohlendorf came out of the second game of the Detroit series after being unable to sustain velocity. Left-hander Xavier Cedeno was called up again from Triple-A Syracuse. If the Nationals don't select Craig Stammen on their 25-man roster, without Ohlendorf, they would have to either pick up a free agent starter or pick one from the minors. Not having Ohlendorf available would mean Stammen's importance as a long reliever is now even more crucial. So Stammen as spot starter even seems like a remote possibility. Danny Rosenbaum might be a choice from Syracuse, but Nathan Karns, who pitched last night, already has experience with the Nationals this season. The other Double-A Harrisburg candidates include right-hander Rob Gilliam (3-5, 4.09), right-hander A.J. Cole (2-0, 0.69), left-hander Robbie Ray (3-1, 3.24) or right-hander Taylor Hill (2-5, 2.49). Cole is a long term hot prospect and Ray has made a considerable jump this year. Hill has done a nice job and Gilliam has had his moments. Karns has lost his last two minor league starts, but has proved to be a workhorse with back-to-back eight inning performances and 19 strikeouts. He was 0-1 with a 7.50 ERA in three starts with the Nationals this season. He has pitched consistently in the past 10 starts for Harrisburg, with a 3-3 record and a 2.79 ERA. Last night was a hard luck 3-2 loss, he pitched well with eight innings and 11 strikeouts. When Jordan is shut down in five or six starts because of his mandated innings limit, I would think Karns would be the choice to get another shot at the fifth starter spot. But Ohlendorf could also come off of his disabled list stint around August 16, so if he is recovered from his shoulder inflammation, he could slide into the starter role as well when Jordan is shut down.