Cardinals manager Oliver Marmol said Wednesday that Walker has been diagnosed with inflammation in his left knee following an MRI, Daniel Guerrero of the St. Louis Post-Dispatch reports.
The news is good, as Walker is not dealing with any structural damage after tweaking the knee when he stepped on a sprinkler head while pursuing a flyball during Grapefruit League play Tuesday. He will miss around a week of games in order to allow the knee to "calm down," per Marmol, but it doesn't sound as though Walker's Opening Day availability is in doubt.