It's over with. There are no mulligans in baseball.
He is scheduled to pitch again on Friday afternoon against the Cubs at Wrigley Field.
There is no time for hangovers from that Sunday fiasco in which Cain handled St. Louis hitters easily for three frames, needing only 30 pitches, and then couldn't get out of the fourth, when he became the first Giants pitcher in more than 100 years to give up nine runs in an inning.
"You look at what happened, try to fix it and then move on," said Cain.
It's called short-term memory.
Cain sounds like he has mastered that. Asked if he could remember any time he had endured something like that 36-pitch, 11-batter endeavor against the Cardinals, Cain smiled.
"There is probably something, but those are the things you try and black out of the memory," Cain said. "Some times can be harder than others."
The fact Cain was on the big league stage last Sunday, on a day the Giants had a pregame ceremony to hand out the 2012 World Series championship rings, brought a little more attention to the events.
Cain was the first Giants pitcher to give up at least nine runs in an inning since Ernie Shore gave up 10 runs, three earned, in his Major League debut with the New York Giants in 1912. And he was the first Giants starting pitcher to give up nine runs in an inning since Jack Cronin in 1902.
Shore didn't get back to the big leagues until 1914, with the Boston Red Sox, but he wasn't deterred by that dubious debut. He pitched six big league seasons with the Red Sox and New York Yankees, and was 65-43 with a 2.47 ERA.
And it could have been worse. Tony Mullane set the all-time record when he gave up 16 runs in the first inning of a June 18, 1894, start with Baltimore, and Lefty O'Doul holds the modern-day record, allowing 13 runs in the first inning of a July 7, 1923, start for the Boston Red Sox.
"We are all susceptible to doubting ourselves,'' admitted Giants left-hander Barry Zito. "That's a certain side of this game that is going to be there no matter what you accomplish.''
Cain has handled adversity of his own, even if it hasn't come often for the right-hander, who has been the most consistent member of a rotation that is the foundation for a Giants team that has won two of the last three World Series.
He has never given up nine runs in an inning, but he did allow nine runs in an April 18, 2008, start against St. Louis. The next time out, he gave up one run in seven innings against San Diego.
After allowing eight runs in a July 9, 2010, start against Washington, he bounced back with a seven-inning, two-run effort against the Mets. And an eight-run game against the Cubs on May 10, 2006, was followed up by two perfect innings of relief, and then a one-hitter against Oakland.
"It's all part of baseball,'' said Zito. "If you are in this game long enough, you are going to experience the full spectrum.''
Cain got a full experience against the Cardinals in an inning in which he gave up six singles and a double, walked two, got one out on a sacrifice fly and the other when St. Louis pitcher Adam Wainwright popped up a bunt.
"Crazy things happen sometimes,'' said Giants catcher Buster Posey. "You'd think at some point a ball would be hit at somebody, but they just kept falling in.''
And it seemed like it took forever.
"It was like quicksand,'' said Cain. "A slow death."
The successful, however, overcome the doubts.
And Cain has been successful.
The Giants' first-round Draft pick in 2002, Cain has won 12 or more games and pitched more than 200 innings in each of the last four years, compiling a 55-35 record and a 2.93 ERA. He has received votes for the National League Cy Young Award each of the last three years. And he is 4-2 with a 2.10 ERA in eight postseason starts in 2010 and '12.
Posey said it wasn't like there was a mechanics mess to clean up on Sunday.
"I went out to the mound to just give him a chance to slow down,'' said Posey. "Matt's not a guy you have to say too much to. He's pitched eight years in the big leagues, so he's doing something right.
"He's such a professional. He's going to be fine.''