In the fourth start of his return from a lower back strain, Kershaw allowed the first grand slam of his career, erasing a two-run lead in an eventual 4-3 loss to the last-place Phillies.
He wasn't even satisfied with his five scoreless innings to open the game, much less the rocky sixth.
"No progress," Kershaw said bluntly. "We had the lead, I blew it and we lost. Not a lot of progress to be had. Go back to the drawing board and get ready for the next one."
Kershaw hung a 1-1 slider to Aaron Altherr and it was blasted into the upper deck in left field. After missing five weeks with the back strain, a year after missing 2 1/2 months due to a herniated disk, the three-time Cy Young Award winner looked human Monday, even though he possesses a 17-4 record and 2.26 ERA.
"It wasn't great, really, all night," Kershaw said. "I had trouble putting guys away with two strikes, threw a lot of extra pitches, and it caught up to me, I guess."
Having pitched 163 innings, Kershaw already has allowed 21 home runs, five more than his previous career high. His strikeout-to-walk ratio is the lowest it has been since 2013, with the hits per nine innings the highest since 2012.
Manager Dave Roberts doesn't dispute the stats, suggesting that slugging percentages are up across the Majors. He acknowledges that Kershaw's fastball velocity is down (in the 92-93 mph range), leaving less margin for error.
"The velocity [is] down a little, but he can make pitches at 92," he said. "When the slider's right, it's still as good as I remember it. The breaking ball's the same. A sequence here and there, but as a whole, he's getting where he needs to be."
Kershaw will look to get to the top of his game for a postseason that begins in less than three weeks. He has been erratic in four starts since returning. On Monday, he issued a pair of walks after being ahead in both counts, 1-2, before allowing the Altherr homer.
"It was a surprise to all of us," Roberts said of the slam. "When there is traffic or stress, he always finds a way to get the strikeout or ground ball."
Roberts isn't panicking about the possibility of Kershaw not being Kershaw come October.
"I think it's right where you would expect," Roberts said of the comeback. "As we look forward to the postseason, he's going to be where he wants to be. He's at four [starts] and he's trending the right way.
"We're still talking about one of best pitchers in the game. I just don't want to make too much out of one inning or one pitch."