PHOENIX -- With hopes of making the postseason, the Reds waited two months for Hunter Greene to return from a hip injury and boost their rotation for a stretch run. In many ways, they're still waiting for Greene to help them.

Greene's latest effort saw him give up all five of his earned runs in an interminable fourth inning. Lackluster defense also contributed to the 10-8 loss against the D-backs on Friday night at Chase Field.

The close score -- aided by two home runs from Nick Martini and Will Benson's ninth-inning grand slam -- shrouded the Reds having to play catch-up much of the night after trailing, 5-1, in the fourth inning.

Besides five earned runs allowed over 3 2/3 innings, Greene also gave up five hits and walked five with four strikeouts while throwing 90 pitches. 

“Just deep counts, even from early on in the game," Reds manager David Bell said. "Not enough strikes with the fastball. That made it tough on him. He just had to work too hard to get outs. It caught up there at the end of his outing.”

Having lost back-to-back games, the Reds dropped to one game behind the Cubs for the third National League Wild Card berth while Arizona moved up to the second spot. Cincinnati needs just one win in this pivotal four-game series to secure the season-series tiebreaker advantage.

Two starts into his return from the injured list, Greene has a 17.55 ERA with 14 runs (13 earned), 15 hits and eight walks over his 6 2/3 innings. He spent considerable time while on the IL trying to build core strength to alleviate hip and back issues. 

With that behind him, are Greene's issues rust-related or mechanical?

“I’d like to think it’s those things," said Greene, who signed a six-year, $53 million contract on April 18. "It’s part of the game, it’s very frustrating."

“We know he’s working back from the injury. It’s never one thing," Bell said. "Probably smart to take a closer look at it over the next few days. Just from quick observation, not enough strikes with his fastball, not locating his fastball the way he wants to. Not only to get outs, but just to make it easier on him.”

Greene gave up one infield hit through three innings, on a play where he unsuccessfully tried to stop Christian Walker's grounder toward first base and was late covering the bag.

With one out in the fourth inning against Greene, things came apart. Lourdes Gurriel Jr. lined a hit to center field, and as he stopped rounding first base, TJ Friedl's throw missed the cutoff man. Gurriel reached second base with what was credited as a double. Alek Thomas followed with a single to right field that scored Gurriel, but he took second base when Will Benson overthrew the cutoff man to the plate.

Following a walk that loaded the bases, Jace Peterson hit a two-run triple to right field. After back-to-back four-pitch walks with two outs, the inning's ninth hitter -- Tommy Pham -- added an RBI single and finished Greene's night.

“Not being able to execute my pitch when I needed it," said Greene, who is 2-6 with a 5.06 ERA in 16 starts. "I’ve got to be able to flip it from the play in center field. TJ has picked me up a million times and I tried to pick him up right there and wasn’t able to do that.”

Thanks to four innings and 74 pitches of relief work from Brett Kennedy, Bell didn't have to burn through his bullpen after Greene's short night. Kennedy had been on standby to pick up reliever innings the past couple of days, but was likely to start on Saturday. The club announced after the game that Fernando Cruz will start instead. Ben Lively flew to Phoenix on Friday and could be activated from the IL Saturday to take down some innings. He hasn't pitched in the big leagues since Aug. 1 because of a right pectoral strain.

The Cincinnati rotation, which is ranked 28th in MLB with a 5.37 ERA, did not get help at the Trade Deadline on Aug. 1, while the club has gone 8-14 for the month.

On the same Sunday that Greene returned with a disastrous three-inning, nine-run start vs. Toronto, fellow starter Nick Lodolo had a setback on his rehab assignment. Lodolo, who was also being counted on to help the final month, endured another stress reaction to his left tibia.

This makes Greene turning things around even more paramount for the Reds.

"Obviously, a lot of work to do and I just have to get back after it tomorrow," Greene said.