http://www.afl.com.au/news/newsarticle/tabid/208/newsid/122274/default.aspx
Wouldn't have been surprised if they rested him but still doesn't sound too good.
Kerr, who missed three games between rounds 17 and 19 with hip, glute and hamstring soreness, will miss his second straight match with a back injury.
The 28-year-old made a five-minute appearance at West Coast training on Monday afternoon.
"'Kerry' has not responded as well, he's still pretty stiff," coach John Worsfold told 6PR. "He'll up his running program this week and hopefully we'll have him feeling really good next week."
Wouldn't have been surprised if they rested him but still doesn't sound too good.