But his manager had no such doubts after Hernandez quieted the Yankee Stadium crowd of 47,067 on a muggy afternoon in the Bronx.
"That was special stuff today," Mariners skipper Eric Wedge said. "I told him, that's probably the most impressive start I've ever seen as a manager. And I've seen a lot of good and great pitchers over the years. This ballpark, that lineup, the swings and misses, the miss-hits, with so many good hitters over there, the efficiency in which he did it, in a 1-0 ballgame ... it doesn't get much better than that."
The shutout was Hernandez's third in his past eight starts, raising his career total to seven. It was his second 1-0 victory of the season; he beat the Red Sox by the same score on June 28.
The Yankees' only hits were a first-inning double by Robinson Cano and a third-inning single by Ichiro Suzuki. Hernandez finished with six strikeouts and two walks while throwing 101 pitches.
"We'd love to score some runs, but unfortunately, Felix was outstanding," said Yankees shortstop Derek Jeter, who went 0-for-4. "Robbie hit that double in the first inning, and after that we didn't really have anything going.
"He was strike one on everybody," Jeter said. "You can't go up there and try to take pitches when the guy's throwing strikes. Today he was better than us. That's pretty much all you can say."
Hernandez has been as good as any pitcher in the Majors over his past 10 starts, going 6-0 with a 1.41 ERA and 75 strikeouts in 76 1/3 innings. His ERA has dropped from 3.70 to 2.63 in that span, and his six-game win streak is tied for the third-longest in his career.
Seattle evened the series with the Yankees going into Sunday's finale and has now won eight of its past nine in improving to 51-58. The Mariners are 15-6 since the All-Star break, the second-best record in the American League.
Seattle scored its only run in the second when first baseman Mike Carp fought off a 3-2 pitch by Hiroki Kuroda for an RBI single to left. That two-out hit came after catcher John Jaso doubled to lead off the inning.
"That was huge," Jaso said of Carp's at-bat. "It's tough with Kuroda doing situational stuff, hard to lift that hard sinker into the outfield. That hit was huge. I mean, that won the game, and Felix took it from there."
Hernandez doesn't usually need much to work with at Yankee Stadium, where he's now 4-1 with a 1.13 ERA in five starts at the new facility. What's with his love for the Big Apple?
"I don't know, man," he said. "I'm just trying to throw a good game here. You know New York is a baseball city. The fans here love baseball, so I'm just trying to have a good game."
Hernandez is 5-0 with Jaso behind the plate, and the catcher said this was the best he's seen the Mariners' ace use all his pitches in the same game. Brendan Ryan, who has worked behind him the past two years at shortstop, certainly agreed.
"I think he could have gone 15 innings," Ryan said. "Getting that first-strike curve over a couple times and having every bit of sharpness as it did in the first, wow. But that changeup, it defies science."
Several New York writers tried asking about why he's been so loyal through the Mariners' rough past, and Hernandez stuck with his familiar refrain, saying he loves Seattle and is optimistic about the team's young talent.
On this day, the Mariners backed him up with some smart defense, moving into a shift that took away what normally would have been singles to right field by Curtis Granderson in the first and Mark Teixeira in the fourth. Instead, second baseman Dustin Ackley fielded both ground balls in short right field and threw out the runner at first.
Kuroda allowed just the one run on seven hits in 6 1/3 innings before being lifted after he hit Ryan in the left elbow in the seventh. Ryan was replaced by utility infielder Munenori Kawasaki, but X-rays revealed no broken bones.
Ichiro extended his hitting streak to 11 games -- all 11 games he's been with the Yankees -- with a third-inning single. Interestingly, he's had just one hit in each of those games after a 1-for-3 outing Saturday.
Carp has been on a pretty good roll of his own as he went 2-for-4 with a double, making him 13-for-31 (.419) over his past nine games. Jesus Montero, Jaso and Eric Thames also had two hits each for Seattle.