Rockies learning on fly in NL West

with him crumpled beneath Blackmon in the outfield grass. But he is not making many mistakes. His manager is grading Tapia’s defense with a stern eye.

“I think average, on the scouting scale,” Black said Saturday.

In the second inning, Dodgers shortstop Corey Seager lined a hit at Tapia. Los Angeles catcher Austin Barnes called out the rookie, rounding third in a sprint to test Tapia’s arm. The throw came in hot, in plenty of time to nab Barnes, but it was off line and a foot short. It gobbled up Colorado catcher Tom Murphy, who tried to play a short-hop, but missed, and Barnes scored without a slide.

“It was a strong throw. It had strength behind it. It had carry to it. But it was off line,” Black said. “It wasn’t that bad. Was it a great throw? No. Because it was off line. The ball is coming in, he has to short-hop it.”

Like the throw, the Rockies are good, but perhaps not great. They retained the third-best record in the NL after three consecutive losses Wednesday through Friday, including two in a losing series to the Arizona Diamondbacks at Coors Field. But they are now in third place in the stacked West division.

“We have to tighten it up,” veteran Ian Desmond said. “We have to play better. There are ebbs and flows to a season, but this is one of those times when we need to pick it up.”

The Dodgers nitpicked the Rockies into their eight consecutive victory. With Gonzalez on the mend and Gerardo Parra on the disabled list with right quadriceps strain, Black is leaning on Tapia to fill out the outfield, in a similar way to how they turned to four Rockies rookies to bolster a starting rotation. Murphy, too, behind the plate.

They are, in the face of mounting pressure, playing with verve.

“When you love what you do, you have fun,” Tapia said. “And I love what I do.”

Right-hander Jon Gray, working back from a broken left foot, struck out six, walked four and gave up a run on five hits for Triple-A Albuquerque in a rehab assignment. He threw 94 pitches in five innings. His next start likely will be in Arizona for the Rockies this week . ... Gonzalez continued to receive medical treatment on his right shoulder through the evening Saturday and into the game. But he was available to pinch hit, Black said. Gonzalez tweaked his right shoulder in an at-bat Wednesday, then was removed during Thursday’s game when the injury became untenable. … Right-hander Chad Bettis threw a 30-pitch bullpen session at Dodger Stadium. Nick Groke: ngroke@ denverpost.com or @nickgroke