Athletics correspondent Casey Tefertiller brings us the latest injury news on some of Oakland’s most promising young arms. Be sure to check out all of Casey’s work with our Organization Reports. He writes:

Sometimes things are just too good to be true.

The A’s system began the year with a surfeit of pitching talent, much of it acquired in a series of trades during the offseason. Within a week, there has been a significant talent drain, as a series of injuries have hit the system.

Righthander James Simmons, Oakland’s first-round pick from UC Riverside last year, went down with a tired arm, enduring what was described as a dead arm period during his last three starts for Double-A Midland, according to A’s farm director Keith Lieppman. Simmons will meet with doctors in the Bay Area for further diagnosis.

Lefty Brett Anderson, acquired from the Diamondbacks in the Dan Haren trade, went down with a left thumb strain, which prevents him from properly gripping the ball. Anderson was placed on the high Class A Stockton disabled list.

Fautino De Los Santos, the flame-throwing Stockton righthander acquired from the White Sox in the Nick Swisher trade, has gone down with a sore elbow.

At the major league level, the A’s bullpen changed dramatically during the course of a few days. Righthanders Andrew Brown and Santiago Casilla both got of to impressive starts as they helped the A’s to a surprisingly successful first six weeks. Then Casilla went on the disabled list with a sore elbow just days before Brown had to have an appendectomy.