"The Rockies' opening-day starter might be robbed of another closing kick. Aaron Cook was placed on the 15-day disabled list Saturday and will undergo an MRI on his strained right shoulder Monday. Manager Jim Tracy anticipates Cook will miss three-plus weeks at the minimum.

That means with any setback, Cook will run out of time in the regular season.

"I will have more information for you on Monday, but he's going to be out for a while," said Tracy, comparing Cook's injury to that suffered by Franklin Morales, who missed a month earlier this season.

This marks the third consecutive season Cook has been hit by late-season injuries. He lost time in 2007 with a strained oblique and last season with a back problem. In his last three outings, Cook went 0-3 with a 12.19 ERA."