Bad news continues to haunt the Rockies.

Left-handed starter Brett Anderson, who left Tuesday's game against the Chicago Cubs in the fourth inning because of back spasms, is still in a great deal of discomfort.

He already is on the 15-day disabled list and the fear now is that the back injury could be season-ending.

Anderson underwent an MRI on Friday and the team is still awaiting results of the test.

"He underwent the MRI to see if there is possible disc involvement," head trainer Keith Dugger said. "We will wait and see on the results, but he's still in a lot of discomfort."

If the MRI shows there is an injured disc in Anderson's back, he likely would be done for the season. According to Dugger, Anderson has previously never had back issues.