From Brian McTaggart, LaTroy Hawkins did not join the Astros on the trip to Chicago on Sunday, and will have an MRI on his back.
"He's been pitching with an upper back strain and shingles. We just want to see if the discomfort is a strain or a side effect of the shingles. He has been pitching with this for awhile."
LaHawk is expected to join the team in time for Monday night's game.