The Mets released a statement on their official website with an update:
Scott Atchison was seen today in Florida by Dr. James Andrews for continued discomfort in his right elbow. Dr. Andrews concurred with Mets physicians on the diagnosis of, and a treatment plan for, a bone spur in the elbow. Scott will recommence his throwing program on his return to Port St. Lucie. There is no immediate timetable for his return to the Mets in New York.
Before hitting the DL, Scott Atchison had appeared in 19 games. He pitched 18.0 innings to the tune of a 4.50 ERA and a 1.44 WHIP. The Mets pen feels like a wreck right now, so any veteran help could definitely be useful. On the topic of veteran help, David Aardsma has been effective during his stint in Vegas (7.0 IP, 3 SV, 5 H, 1 ER, 10 K) and could be on his way to Flushing soon.