"At the first moment, I had no clue," Heredia said with teammate Nelson Cruz serving as his interpreter. "I just decided to go get it, and at the end I just came up with it."
Instead of a homer, Simmons wound up with a sacrifice fly that cut the lead to 4-3 and Heredia wound up with a highlight-reel catch -- and likely a few bruises.
Heredia acknowledged the wall slam hurt, but all he was feeling afterward was the admiration of his teammates.
"This kid has been playing incredible defense," said shortstop Jean Segura, who had four RBIs and the game-winning hit. "He stepped up, made the team out of Spring Training and came here and battled and now he's got a job every day in left field. That was one the most amazing catches I've seen."
Teammate Jarrod Dyson had the perfect view from center field.
"I call him the home run robber right now," Dyson said. "He's playing great defense, swinging the bat well. What more can you ask from that guy? He's been doing his job. To be young and be a rookie up here, he's holding his own."
Heredia took over the everyday left-field role about 10 days ago when center fielder Leonys Martin was designated for assignment and Dyson moved to center. He's hit .286 with a pair of homers and provided outstanding defense.
"He just continues," said manager Scott Servais. "The at-bats, the energy, the defense, how he goes about it. I'm really happy for him and happy we got him. He's been a big plus for us."
Heredia was known as a standout defender in Cuba before defecting in 2015. He played 45 games for Seattle as a late-season callup last year, but he's getting his first extensive time now. And, no, he's never made a catch like that before.
"Not like that one, no," he said with a grin.
The Angels pushed across three more runs that frame anyway, scoring six times to take a 6-4 lead, but the Mariners would rally in the eighth for the win.