LOS ANGELES – This is not what they paid for.

The Dodgers committed over $740 million to seven free agent pitchers over the past two offseasons. Only two of them — Yoshinobu Yamamoto and Tanner Scott — are currently on the active roster. Fourteen pitchers in all are on the Injured List, an egalitarian group that features the old (Kirby Yates) and the young (Roki Sasaki), the homegrown and the imported.

Stitching together a pitching staff from the available parts has been “not fun” — Andrew Friedman’s description for watching his best-laid pitching plans dissolve over the first two months of the season.

The same two-word assessment applied for watching the pitching struggles continue in a 9-5 loss to the Arizona Diamondbacks on Monday night.

The loss was the Dodgers’ fourth in a row, their longest losing streak this season, during which their pitchers have given up 32 runs.

It’s not just this (very) long weekend, though. Over their past 15 games (6-9), they have a staff ERA of 5.37 with 27 home runs allowed in the 15 games. For the season, all of the Dodgers’ investments in pitching have produced a 4.41 ERA that ranks 24th in the majors.

In Plan A, Jack Dreyer and Landon Knack would have been bit players on the margins of the Dodgers’ pitching staff. But they were sent out — Dreyer to open, Knack for bulk — in the series opener against the NL West rival Diamondbacks. It didn’t go well.

The defense let Dreyer down in the first inning. Hyeseong Kim lost a fly ball in the dusky sky for a double that led to two runs. In the second inning, Dreyer’s wild pitch set up another run.

Knack took over in the third inning and the Diamondbacks teed off. Five of the first six batters he faced reached base and four scored on a pair of two-run home runs by Lourdes Gurriel Jr. and Gabriel Moreno. That put the Dodgers down 7-0 before many fans could bite into their first Dodger dog.

Meanwhile, Brandon Pfaadt held the Dodgers’ bats in check.

Pfaadt retired the first 10 Dodgers in order and gave up plenty of hard contact — eight balls with exit velocities of 100 mph or higher in his six innings — while not getting a single swing-and-miss on any of his 95 pitches.

Three of the high-speed hits by the Dodgers did manage to avoid any Diamondbacks gloves. Solo home runs by Mookie Betts in the fourth inning and Shohei Ohtani and Betts in the sixth were the Dodgers’ only hits off of Pfaadt.