Fields (groin) was placed on the 15-day disabled list Wednesday, Jose de Jesus Ortiz of the Houston Chronicle reports. Fields' DL stint will be backdated to March 27, allowing him to return as soon as the second week of the season. The right-hander seems optimistic about his recovery thus far, and may be back in the minimum 15 days if he's able to continue throwing in the next few days. Fields, who whiffed 70 batters and showed an improved walk rate over his 54.2 innings last season, figures to work in a setup role for closer Luke Gregerson once he's activated from the DL.