HOUSTON -- It was an emotional start for left-hander Andrew Heaney, taking the mound for the first time since the death of his teammate and close friend Tyler Skaggs on Monday.

Before his first pitch, Heaney went to the back of the mound to inscribe "RIP 45" in the dirt and paid tribute to Skaggs with a slow, looping first-pitch curveball to George Springer to begin his outing. Heaney pitched well, allowing two runs over five innings, but it wasn’t enough in a 4-0 loss to the Astros on Saturday night at Minute Maid Park.

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“I didn’t want to do anything that wasn’t genuine, that wasn’t who I feel I am,” Heaney said. “I thought it would be kind of cool. When you talk about Skaggs in the baseball world, the first thing everybody would talk about was his curveball. That was his calling card. That was his claim to fame. I thought it would be kind of cool. Honestly it was just something that felt right.”

Catcher Dustin Garneau explained that Heaney told him about his plan to throw a first-pitch curveball on Friday and that he let both Springer and home-plate umpire Chad Fairchild know it was coming. Springer was told he was free to swing on the pitch, but he declined and took it for a ball.

"The catcher told me that he was going to throw a really slow curveball in honor of Skaggs, and I told him I would take it for sure,” Springer said. “Obviously, the Angels are dealing with a hard thing right now so I don't like to talk about it. But for a guy like [Heaney], I absolutely respect him. It's an honor to be a part of it, and I hope he got something out of it. It's just a good moment for our sport.”

Heaney, who doesn’t throw a curveball as part of his arsenal, threw his first-pitch curve so slow it wasn’t picked up by the stadium’s radar gun and was called a ball by Fairchild, although it appeared to be a strike. Heaney went on to throw a scoreless first frame, including getting Springer to fly out to right.

"It was a nice tribute by him first pitch of the game, throwing the curveball from the rafters as Skaggsy would say," Angels manager Brad Ausmus said. “I still think the pitch was a strike. But he pitched well. I'm sure it was emotional for him pitching out there today but he's braved it as well as anyone could when you're that close to the person who passed away.”

Heaney cruised until the fourth, when he gave up back-to-back singles to open the inning and nearly got Yuli Gurriel to ground into a double play. He struck out Robinson Chirinos for the second out with runners at the corners, but surrendered a two-out RBI single to Josh Reddick on a 0-1 sinker that caught too much of the plate.

Heaney was hurt by a walk and the Crawford Boxes in left field, as he allowed a two-out RBI double to Alex Bregman to score Springer after he walked with one out in the fifth. Bregman’s double hit high off the wall, but it wasn't particularly hard-hit, as it had an exit velocity of 89.8 mph and an expected batting average of .050, per Statcast.

"Really just a couple balls through the shift, and then the pitch to Reddick was supposed to be a fastball down and away, just kind of leaked it arm-side," Heaney said. "He got enough of it to get it out there. The at-bat to Bregman, I'd gone soft the whole time. Got to 3-2, and was a little bit in-between. I kind of cut it a little bit, but it stayed middle up and that's a pitch that he usually handles pretty well. It got in on him a bit, but just enough to score the run there."

Heaney departed after five innings and 85 pitches, finishing the first half with a 5.18 ERA in eight starts. Heaney struck out five, walked two and gave up five hits, while keeping his emotions in check.

"He was unbelievable,” Garneau said. “He was probably the one closest to [Skaggs] in the locker room. He's been emotionally up and down all week. You could see it on his face. But the way he controlled it in the game, he threw a really good game and only missed on two fastballs that went both ways. But other than that, he pitched against one of the toughest lineups in baseball with a weight on him, whether he's going to say it or not."

Right-hander Trevor Cahill replaced him in the sixth and promptly served up a solo shot to Gurriel to right, giving him his fifth homer in his past four games. Cahill later gave up an RBI double to Yordan Alvarez in the seventh.

The offense, meanwhile, couldn’t muster anything against right-hander Gerrit Cole, who scattered three hits over seven scoreless frames with nine strikeouts. Cole reached 100 mph on his fastball a career-high seven times, including 101.1 mph on his 110th and final pitch of the night to strike out Jarrett Parker to end the seventh.

"He's one of the best in the league for a reason,” Ausmus said. “[His] fastball-slider combo is two of the better pitches in those categories. If a guy like Cole is on his game, it's tough for hitters."