It will be a Zack-attack Monday night as the Kansas City Royals meet the Arizona Diamondbacks in Phoenix. Or will it be a Zach-attack?

The Royals will send Zack Greinke (0-2, 3.48 ERA) to the mound to face fellow right-hander Zach Davies (2-2, 4.35).

To confuse things further, the Diamondbacks will start Zac Gallen on Tuesday. But that's another story.

The Royals enter the two-game series in a bad mood. For the second straight Sunday, they blew a 6-0 lead. Unlike the previous Sunday, when they allowed the Colorado Rockies to score seven consecutive runs but came back to win 8-7, they couldn't duplicate the result, falling 7-6 to the Twins a day ago.

The Royals have lost four in a row.

The Diamondbacks were going for a sweep of their own on Sunday but fell 5-4 to the Cubs in Chicago. Arizona trailed 3-0 after two innings but took a 4-3 lead heading into the bottom of the eighth. Ian Kennedy gave up back-to-back home runs to Patrick Wisdom and Frank Schwindel in the Cubs' 5-4 win.

Greinke, who spent most of four seasons with the Diamondbacks between 2016 and 2019, is in his second stint with the Royals. The No. 6 overall pick in the MLB Draft by the Royals in 2002, he made his debut with Kansas City in 2004. In his seven seasons there the first time around, he was 60-67 with a 3.82 ERA before being traded to the Milwaukee Brewers. He was 55-29 in three-plus seasons with the Diamondbacks.

Greinke has pitched well for the Royals this season; he's allowed more than two earned runs in just two of his eight starts. In his last start, he gave up two earned runs on seven hits in 5 2/3 innings against the Chicago White Sox.

"He's a joy to watch," Royals manager Mike Matheny said of his veteran ace. "That's pitching at its finest. He manipulates and makes minor adjustments, figuring out ways to get the break he wants on his slider, and then he'll toy with his changeup. The stuff he can do midstream you wouldn't want to teach anybody else, but he's very unique. He's doing such a great job of making big pitches in big situations."

Greinke, 38, has wins and losses against every major league team. He is 7-3 with a 3.72 ERA all-time against the Diamondbacks.

Davies had his worst start of the season in his last appearance, allowing five earned runs on seven hits in just four innings at the Los Angeles Dodgers on Wednesday.

He was confident that effort was a temporary setback.

"It's a bump in the road; it happens during the course of a season," Davies said. "Nobody's let down by it, nobody's changed their attitude on it. I'm not really worried about anything."

Davies has faced the Royals twice in his career, splitting a pair of decisions with a 4.50 ERA.