Thursday afternoon's 7-1 loss to the Angels at Chase Field dropped the D-backs to 32-34 on the season.
The last time the D-backs had a breakeven record was April 24, when they were 8-8. Eight times since then they've entered a game just one below .500, and all eight times they've lost.
"I don't know if anybody is even thinking about it in there," D-backs manager Chip Hale said, referring to the clubhouse. "We just didn't play well enough to win and they did."
Allen Webster (1-1) was solid through five innings for the D-backs. It was the right-hander's second start since taking Josh Collmenter's spot in the rotation, and once again he stumbled in the sixth inning.
After throwing a no-hitter for five innings in his start against the Giants on Saturday, Webster was unable to get through the sixth as he allowed a pair of runs.
This time through five, the only damage allowed came in the form of solo homers by Taylor Featherston and Johnny Giavotella in the third.
"He pitched very well for the five, kept us in the game," Hale said. "Just two bad pitches up in the zone that they were able to hit the home runs on."
Still, it was a struggle for Webster to keep the ball in the strike zone. His two-seam fastball had so much movement to it that it often dived out of zone.
"It's always a challenge," Webster said of his command. "I didn't have my command that I had the previous game, but went out there and battled."
Double plays wiped out walks in each of the first two innings, and he hung in there until the sixth.
"I just felt like when I took him out that he had walked a guy on four pitches and he just seemed like he didn't have anything left," Hale said. "I just didn't think he had anything left to throw strikes."
Collmenter allowed all three of the runners inherited to score, which made Webster's final line ugly: six runs and five walks in 5 1/3 innings.
"In the sixth, I just lost control a little bit," Webster said. "I still felt strong. They just weren't going where I wanted them to go."
That was not a problem for Angels starter C.J. Wilson, who held the D-backs to one run on eight hits while striking out nine in eight innings.
"He was just making good pitches," D-backs first baseman Paul Goldschmidt said. "He mixes it up with fastballs, sliders, curve, change, but he didn't make many mistakes, and when he did, we weren't able to take advantage of them. We needed to do a better job. One run is not going to win many ballgames. You've got to give him credit, but we have to find a way to kind of come through. I had a couple of opportunities personally and wasn't able to do anything."