Nathan said Friday he was diagnosed with a Grade 1 strain of the elbow flexor, Jason Beck of MLB.com reports. Shortly after Nathan hit the DL on Wednesday, Tigers GM Dave Dombrowski told MLive.com that the team was "hopeful he will be fine at the end of that 15 days." While Nathan also seems optimistic with the diagnosis of a Grade 1 strain, he will not be allowed to pick up a baseball until the tightness is completely gone. Joakim Soria will get a chance to hold down the closer role in Detroit in the meantime.