DENVER — Eddie Butler has struggled in his short time with the Colorado Rockies.
Jon Gray hopes to have a better start when the Rockies introduce their top pitching prospect Tuesday.
Butler stumbled through another rough start, allowing seven runs in four innings as the Seattle Mariners beat the Rockies 8-7 on Monday night.
"I didn't have a feel for much today," Butler said. "The fastball was the only thing I could put in the zone with any authority. I had one pitch and they were able to hit it."
Felix Hernandez pitched effectively into the seventh inning and Nelson Cruz homered in a fourth consecutive game to reach 30 for the season for the Mariners, who held on in the ninth for the win.
Butler's forgettable outing came on the eve of the major league debut for right-hander Jon Gray. Gray, the third overall pick in the 2013 draft, will start the second game of the series.
"Jon will handle it very well," Rockies manager Walt Weiss said. "He's grown up a lot in the last year. And he's ready for this."
The Rockies hope Gray's first game goes smoother than Butler's start to his career. Since making his debut June 6, 2014, Butler is 4-9 with a 5.70 ERA.
Seattle jumped on Butler with a four-run first highlighted by Jesus Montero's two-run double. Butler (3-8) also allowed three homers in losing a third straight decision. All of the runs he allowed scored with two outs.
"The first inning just got out of hand. I wasn't able to stop the bleeding," he said. "That was the downfall. I put us in a big deficit and with Felix pitching it's going to be hard to score runs."
Kyle Seager and Cruz went back-to-back in the second inning to put Seattle up 6-1. Cruz's homer extended his hitting streak to 14 games.
Brad Miller connected for his ninth of the season in the third.
"When Eddie's got the command he's in good shape," Weiss said. "It's a tough league to pitch in bad counts."
Jose Reyes, in his first appearance at Coors Field since being acquired by Colorado in the trade deadline deal that sent Troy Tulowitzki to Toronto, had two RBI singles. Charlie Blackmon added four hits, including two doubles.
Trailing 8-4 heading into the bottom of the ninth, the Rockies scored three runs and had runners at the corners with two outs before Carson Smith induced a game-ending fly out from Blackmon for his 10th save.
"Having him with the game on the line, I'll take that every time," Weiss said.
Bouncing back from a rough start last time out — Hernandez allowed seven runs in Seattle's 8-2 loss to Arizona last week — the Mariners' ace went 6 2-3 innings and allowed four runs and 11 hits. He improved to 8-0 with a 1.65 ERA in 12 starts following a loss since the beginning of last season.
Hernandez (13-6) struck out nine and walked one in his first career appearance at hitter-friendly Coors Field.
After Blackmon's RBI double in the sixth pulled the Rockies within 7-4, Robinson Cano doubled in the top of the seventh to drive in his second run of the game.
DJ LeMahieu had a tough time at the plate after hitting .467 in a four-game weekend series at St. Louis. LeMahieu struck out five times, the last of which came in the Rockies' rally in the ninth. He is the third player in franchise history to strike out five times in a game and the first since Carlos Gonzalez did it at Pittsburgh on July 18, 2014.
He is the second player in the majors to do it this year. The Cardinals' Randal Grichuk fanned five times on May 18 at the New York Mets.
Rockies: RHP Chad Bettis was scheduled to throw a bullpen session on Tuesday, his first since going on the 15-day DL on July 19, because of right elbow inflammation.
Rockies: Gray (0-0) went 3-1 with a 2.70 ERA in six starts last month for Triple-A Albuquerque.