I think Krol or Abbad go down instead. Ohlendorff is a back up starter if Haren, Det, or Jordan don't work out.
I doubt they send down one of the lefties. Krol looks to be a real power pitcher and could be a 7th or 8th inning guy for the club. Abad, although interestingly enough not this year, has been stronger against lefties and probably projects as a lefty specialist like Mike Gonzalez was last year. Stammen is the long reliever of the bunch, even amidst his current struggles, he keeps his job. Hopefully the Nats starting rotation "issues" are figured out and the need to have two long men is put to bed. Mattheus replaces Ohlendorf.