It was an unacceptable performance and Wakamatsu said so, both to Hernandez and the media.
The message was to-the-point and Hernandez has been at the top of his game in five consecutive starts, capped by Tuesday night's stellar two-hitter in the Mariners' 5-0 Interleague victory over the Padres before 17,040 at PETCO Park.
The Mariners got a lot of mileage -- and footage -- from their three hits.
Franklin Gutierrez and Adrian Beltre hit home runs in the third and seventh innings, respectively, and Ken Griffey Jr. delivered a two-run single during a three-run ninth inning that made the final three outs much easier for Hernandez's first complete game of the season.
The only real bummer for the Mariners was right fielder Ichiro Suzuki ending his career-best streak of reaching base at 43 games. He was 0-for-4, but this night belonged to the Mariners' ace.
Hernandez surrendered a leadoff singles in the second and ninth innings and not much in between.
"I have caught him a couple of times, but that has to rate with one of the best performances I have ever caught," veteran catcher Jamie Burke said. "All four of his pitches were working. He had command of everything.
"It was just a matter of which pitch he wanted to use. It was fun to be back there and catch a guy who has command of all his pitches."
Burke said Hernandez's two-seam and four-seam fastballs were sharp, and so were his slider and curveball.
The end result is one of the best games the 23-year-old has pitched in his still-young and improving-steadily MLB career. He said this game was similar to the one-hitter he pitched against the Red Sox two years ago.
"I felt pretty good today," he said. "All the pitches were there. I had great command after the first inning."
And great command of himself, which Wakamatsu has noticed in all five outings since the chat.
Hernandez has allowed just three earned runs in 37 2/3 innings since the Angels game for a 0.72 ERA and perhaps has pitched himself into being a candidate for next month's All-Star Game.
"Everyone talks about how good he can be and we talked about our expectations and his expectations," Wakamatsu said. "It has a lot to do with the little things -- controlling the running game and becoming more efficient.
"It's not just going out and competing. It's trying to be more intelligent. And from that point, I've seen a different pitcher. I've seen a guy that comes out and is ready to compete for his team."
Hernandez went into his 14th start of the season with two wins and two no-decisions in his previous four outings. Three of those starts were stellar, surrendering one run each against the Giants, Twins and Orioles.
He was right back at it against the Padres.
The only predicament he encountered in the first eight innings came in the second, when Kevin Kouzmanoff led off with a single to right field, advanced to second on a wild pitch and moved to third on an infield out.
After a walk to Henry Blanco put runners on the corners, Hernandez retired Luis Rodriguez on a routine fly ball to Griffey in left field.
There was a slight scare in the seventh when, with two outs, Brian Giles walked and Chase Headley sent Gutierrez to the warning track in right-center for the catch.
"It was outstanding," Hernandez said of the running catch. "He's the best in center field. He's great. He's got a lot of range."
"It was a tough play," Gutierrez said. "I was playing him pretty shallow, and he hit it good. I was trying to get there as quick as I could and make the catch."
He made it look easy.
So did Hernandez, and the Mariners definitely needed their ace to be at his best in the series opener.
A team's best pitcher is supposed to stop losing streaks, and Seattle (31-33) entered the three-game series against its Spring Training partners fresh from being swept by the Rockies in Denver.
"Obviously, you look for a guy of his talent to be a stop-gap guy when you go on a little losing streak, to be able to step up and pitch the way he did," Wakamatsu said.
The Padres were coming off getting swept as well, against the Angels in Anaheim, and runs figured to be a premium.
Gutierrez got all of his muscle into the swing he made on a Kevin Correia fastball in the third inning and drove it over the 401-foot sign in left-center field for his fourth home run of the season -- and the longest by far.
The blast went 428 feet.
"I think that is as far as I have hit one," he said. "This is my first time playing in this park and I heard that the ball doesn't carry. I surprised myself. It was good to hit home run in that situation. It put the team up by one run."
It became a two-run lead in the seventh when Beltre hit his fifth home run of the season -- a 395-foot poke into the left-field seats.