"I thought everybody really loved me. Then I looked behind me and I saw Buster," Cain said with a chuckle later.
Indeed, it was that kind of day, a day when a player -- actually two -- just stepping onto the field was worthy of a standing ovation from Giants fans. With Posey and second baseman Freddy Sanchez, who served as designated hitter, making their returns to the field, 2012 already looked brighter than 2011 for the Giants.
Posey was a little nervous. He only played two innings. But this was about the bottom line, and the bottom line is this: Buster is back.
Posey's much-anticipated Cactus League debut Friday afternoon was brief and uneventful, as the Giants catcher received those two innings from Cain and had one chance to bat.
"I haven't played since the end of last May, so I definitely had some nerves -- good nerves, though," Posey said.
Posey hadn't seen any game action since May 25, when Florida's Scott Cousins bowled into him, causing a broken bone and torn ligaments in his lower left leg. Out for the remainder of the 2011 season, the 2010 National League Rookie of the Year came into camp hoping to play his first game in the Giants' Cactus League opener, but Friday was tabbed as the day he'd finally get back behind the plate.
And it could be labeled as nothing short of a success, even with the emphasis on short.
"It was good to see him out there," Giants manager Bruce Bochy said. "I know he was excited about today, and we were for him. I thought he looked good. He looked comfortable catching and moving around, and he made a good throw. It's a tough debut facing somebody throwing that hard."
That somebody would be Reds fireballer Aroldis Chapman, whom Posey faced in the second inning Friday. After receiving another ovation that had many at Scottsdale Stadium on their feet, Posey flied out to right in his only at-bat on a slider from the dynamic left-hander.
Against Chapman, Posey swung once and took another pitch to fall behind 0-2 before taking pitches in and high to even the count at 2-2. He lifted a fly ball to right that Chris Heisey easily hauled in as Posey ran to first and rounded the bag, wearing a protective guard over his left ankle.
He then trotted off the field to yet another ovation, ending a big day for the 24-year-old star.
When the game began, Reds leadoff hitter Brandon Phillips greeted Posey but saved his normal tap on the shinguards he delivers to opposing catchers, giving Posey a few words and a wide smile instead.
"He was just saying, 'Glad to see you back,' nothing more than that," Posey said.
Every one of the 10,000-plus who filled Scottsdale Stadium on a sunny spring day would second that emotion.
Defensively, Posey had no apparent issues. He didn't have to run in his catcher's gear in either inning, which included hits by Reds batters Ryan Ludwick and Miguel Cairo. But he did get the opportunity to block some balls in the dirt, with no problems.
"That was good, and fortunately that's been something that has come back and I haven't had any problems with that as far as the ankle mobility," Posey said. "But it was good to get some in a game."
The Reds did take the first opportunity they had to try to steal against him, with 37-year-old Cairo bolting on the second pitch after he reached on a single in the second. After getting a good jump, Cairo slid in safely just as Posey's throw drilled him in the middle of the back.
Posey was slated to catch only two innings and get one at-bat, and that's what he got out of a debut he and Giants fans had been awaiting for the better part of a year.
For Cain, it was as though he never left.
"Buster didn't skip a beat back there," Cain said. "He had a game plan of what we wanted to do, and he went out and did that. That's kind of the way Buster is. He did that when he first came up."
Bochy said the next step will be for Posey to catch four innings, probably Sunday. Then the Giants will try to get him to seven or eight by the middle of the month or so, before getting him all the way through a nine-inning game late in camp.
Said Posey: "This is part of the process. We'll see how my ankle responds tomorrow. From all indications now, I think it'll be good. We've stuck to the plan the whole way."
So far, so good. Friday's game was a big first step, but there are many others to be taken before Posey is back on the field for real in the regular season.
But that first step felt oh-so-good for Posey and the Giants.
"It was fun," Posey said. "I've put in a lot of work to get back in the game. It was only two innings, but it was nice to be out there."
John Schlegel is a national reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.