The Astros have recalled Robbie Grossman to be the everyday Left Fielder, thus ending the platoon in left in the outfield (Presley and Hoes).
Hoes seems to have been relegated to platooning against LHP's, and as such, hasn't gotten a lot of playing time recently. The radio commentators, in particular, have noted (paraphrasing) that he had a little bit of a slow start to the year, but seems to have been hitting the ball a lot harder recently. Hoes is currently hitting .250/.354/.475 in 48 plate appearances against lefties, and .148/.179/.148 in 29 plate appearances against righties.
Presley is going to stay up for now, but will likely slide a back in the depth chart. He is showing a reverse platoon, hitting .179/.207/.292 in 111 plate appearances against RHP's, and .467/.467/.533 in only 15 plate appearances against LHP's (sample size warning, of course, most likely just noise).
Grossman, after an awful start to the year (.125/.236/.313 in 55 plate appearances) was demoted to Oklahoma City, where he hit .299/.373/.453 in 153 plate appearances.
This move was probably forced by Presley's poor line against righties (and lack of options), with Hoes taking the fall so the Guzman can be the primary right-handed platoon-bat on the 25-man. Hoes will get more at-bats at AAA, and Presley, Krauss and Guzman get another month to decide who gets the boot when Singleton is ready. Krauss, in particular, seems to be hitting the ball harder recently, Guzman may only have a month left, and Presley may be the next to be cycled back to Oklahoma City (should he clear waivers) or DFA'd.
Regardless, Bob Grossman is back, and expected to start in left in Kansas City on Monday.