"You just stand over there and it's like, 'What is he doing? It's too hot for this,' " Santiago said.
Santiago's workday ended well before the Angels won, 3-2, when Kole Calhoun scored from third base on a 10th-inning wild pitch by reliever Tom Wilhelmsen.
But Santiago, a 27-year-old left-hander, left a terrific impression.
"There's no doubt Hector Santiago is an All-Star-caliber pitcher this year," Angels Manager Mike Scioscia said.
Santiago gave up a run and three hits in seven innings. He struck out six batters and lowered his earned-run average to 2.58.
He did not figure in the decision, but if he continues to pitch the way he has lately, he could make it difficult for Kansas City Royals Manager Ned Yost not to include him on roster for the July 14 All-Star game at Cincinnati.
Santiago said the key to his success this season was improved mechanics.
"Understanding my body, understanding mechanics and just making adjustments," he said.
On Sunday, Santiago retired the first 10 batters before Franklin Gutierrez singled in the fourth inning.
Santiago appeared a bit unnerved after he failed to get a strike call on a pitch that would have struck out Robinson Cano. Instead, Cano worked a 10-pitch at-bat for a walk, setting the stage for Nelson Cruz's double off the wall in the right-field gap for a 1-0 lead.
That was all the Mariners could muster against Santiago while the Angels tried to solve Hernandez, the 2010 Cy Young Award winner who has dominated the Angels the last two seasons.
Hernandez gave up one hit in six scoreless innings.
"Hector matched him pitch for pitch," Scioscia said.
Whether that kind of performance will be enough to land Santiago on the All-Star team for the first time remains to be seen.
"There's no doubt he's throwing the ball as well as the top 10 pitchers in our league … however you want to slice it up," Scioscia said. "But the selection process is dicey."
Santiago is 4-4 but has given up no more than one earned run in nine of his last 14 starts.
Closer Huston Street, who gave up a score-tying home run with two out in the ninth inning, said Santiago was worthy of All-Star consideration "because it's tough to put up the type of numbers he's put up this year."
The Angels' victory improved their record to 39-37 and kept them four games behind first-place Houston in the AL West.
On Monday, the Angels open a three-game series with the New York Yankees, who swept the Angels at Yankee Stadium a few weeks ago.
The Angels then embark on a nine-game trip to Texas, Colorado and Seattle before the All-Star break.
Santiago will probably make two more starts before the All-Star game.
That's two more chances to impress.