Kershaw was diagnosed with a lower-back strain Monday, David Vassegh of AM 570 LA Sports reports.
Following Monday's evaluation, manager Dave Roberts confirmed that this ailment isn't as serious as the disc injury that sidelined the ace for two months last season, Bill Plunkett of The Orange County Register reports. The skipper also mentioned that Kershaw is "day-to-day" with the injury, but considering the fact that he's already been placed on the 10-day disabled list, it's safe to assume that 4-to-6 weeks remains the best estimate for his eventual return at this time.