Burton is dealing with a strained lat and will undergo an MRI on Thursday. Burton agreed to a minor league deal in February with an invite to spring training, and has been competing for a spot in the Opening Day bullpen. The 33-year-old reported that he's dealt with a similar injury previously and that he didn't believe this was as serious, but the results of the MRI should give a clearer indication of how long he'll be sidelined for.